[Note:
BtVS/Stargate SG1 crossovers,
Other SG1 Crossovers, and
BtVS/AtS crossovers not involving SG1 are posted separately. Someday, I hope to have a listing of non-crossover fic recommendations to post, mostly based on favorite pairings, but for now I'm tackling the much less daunting task of compiling a list of those few crossover fics that I've read and enjoyed which didn't involve SG1 and/or BtVS.]
Updated 4/24/20 see the rest of this post (which LJ cut off at 1/3 finished on the latest revisions) here -- part 2:
https://revdorothyl.livejournal.com/197803.html and part 3:
https://revdorothyl.livejournal.com/197976.html FANFICS ARRANGED ALPHABETICALLY BY PRIMARY 'VERSE/SETTING:
Avengers (2012)/Marvel Movie Universe/Harry Potter:
--"Post-Apocalyptic Potter from a Parallel Universe" by burnable (Harry Potter/Natasha Romanoff, Tony Stark/Pepper Potts, Bruce Banner/Sif; Logan/May Parker; A traumatized MoD Harry Potter arrives in the Avengers universe after seeing his own earth rendered lifeless by Voldemort before his real final death, and Harry is encouraged by the Ancient One to try to help this world, with the promise of eventually being able to save his old one; excellent Marvel movie universe/"Harry Potter" crossover of worlds and characters, from the first "Avengers" movie through "Endgame", including all the Marvel movies in between -- even "Deadpool"!):
https://www.fanfiction.net/s/13326497/1/Post-Apocalyptic-Potter-from-a-Parallel-Universe --"Green Eyes and Red Hair" by fringeperson (Loki[James Potter]/Natasha Romanov[Lily Evans]; pre-Rogue[Marie Potter, the Girl Who Lived]/Logan; James Potter dies in Godric's Hollow in 1981, only to awaken in Asgard, remembering that he is really Loki who had been condemned by Odin's whim to live yet another lifetime as a mortal on earth, but he's not about to let that keep him away from his latest wife and daughter; meanwhile, Nat-as-Lily survives the AK thanks to some Red Room tech, but is knocked out long enough for Dumbledore to kidnap Marie and try to dump her on Petunia; Loki manages to magically connect with Nat and Marie and send Marie to be adopted by a nice couple in Mississippi, while he and Nat work on eliminating the Red Room and reuniting the family in the flesh, rather than just in the dream world; excellent "X-Men" movie/"Avengers"/"Harry Potter" crossover of worlds and characters!):
https://www.fanfiction.net/s/12661005/1/Green-Eyes-and-Red-Hair --"Mischief Managed" by fringeperson ('Professor' Loki takes over Harry's introduction to the wizarding world and school shopping from Hagrid, and that changes everything! The Runes professor becomes Harry's one trusted adult and father figure, keeping Albus' machinations at bay, while Harry spends his school holidays traveling the world and running across future Avengers):
https://www.fanfiction.net/s/10716582/1/Mischief-Managed (see also one-shot companion/sequel story "Mischief Mastered:
https://www.fanfiction.net/s/10853424/1/Mischief-Mastered)
--"Fates Be Changed" by The Homing Pigeon (Bruce Banner finds a small, wounded, hungry, English-speaking, six-year-old child on the street in India one Christmas Day, and both he and the 'Other Guy' soon adopt the newly named Mateo as his son; the events of the first "Avengers" movie are covered in chapters 13-17 of 69 total, with all the Avengers family becoming Mateo Banner's loving aunt and uncles, after which the HP canon starts to come into play in chapter 21, when Dumbledore finds Harry's Hogwarts letter addressed care of Stark Tower in NYC; tertiary crossover with the BBC's "Sherlock"):
https://www.fanfiction.net/s/11397437/1/Fates-Be-Changed --"My Son the Wizard" by savya398 (Technically unfinished since 2015, with the author still planning to add 3 additional chapters and an epilogue to the existing 20 chapters, but I found this story finished enough for my tastes; Voldemort has yet to be finally defeated, but Harry and his newly discovered biological father Tony Stark have made it through the key events of the movie "Avengers", Harry's battle with the basilisk in his 2nd year at Hogwarts, the escape and innocence of Sirius Black, "Iron Man 3", and "Thor: the Dark World", with Loki on the loose and far from reformed but still planning to drop in on Harry in the future, to annoy his Avengers familly):
https://www.fanfiction.net/s/9514290/1/My-Son-the-Wizard (or
https://archiveofourown.org/works/1561292/chapters/3311240)
--"Cold" by
scifichick774 (pre-Loki/Hermione, possibly to be continued; not-yet-17-year-old Hermione is suddenly orphaned and sent to live with her parents' closest living relative, Agent Phil Coulson, in post-Chitauri New York, where S.H.I.E.L.D. and The Avengers are vainly trying to find some way to control and contain Loki, with the help of some Aurors; only angry, emotionally bereft Hermione seems to be able to magically affect and restrain Loki, and Loki is fascinated by the possibilities):
http://kris-fic.livejournal.com/86820.html --"Changing Destiny" by
sarhea (Loki/Hermione; in an AU of Thor, Loki meets and is intrigued by Hermione, who's living in the muggle world to escape the pressures and expectations of the post-war Wizarding world; consequently, Loki has someone sane to talk to when he discovers his adoptive status and plans to reunite with her upon his return to Midgard in The Avengers):
http://archiveofourown.org/works/687117/chapters/1261336 --"Finding Home" by cywsaphyre (Harry stopped aging more than ten years ago
and has had to accept the necessity to keep moving every few years, in order to conceal his immortality from the world; however, in his new life as an auto mechanic in NYC he attracts the interest and friendship of Tony Stark, and so the events of the first Avengers movie will play out a little differently. Fair warning: the never-likely-to-be-finished sequel goes much darker, as do the one-shots associated with it, so you might want to stop before the part where Death warns Harry that Thanos is coming in a matter of days, rather than waiting six years to attack earth directly):
https://www.fanfiction.net/s/8148717/1/Finding-Home Avengers (2012)/Smallville:
--"The Trickster and the Reporter" SERIES by
sarhea (Chloe/Loki; Chloe winds up in the Marvel universe in time to heal Loki's mind and dramatically alter the events of the first "Avengers" movie):
http://archiveofourown.org/series/32059 --"Shield" by
scifichick774 (possibly to be continued; AU post-series SV Chloe, who's spent years being 'Watchtower' full-time for the Justice League, is ordered by Emil to take a vacation free from aliens, superheros, and supernatural threats, so . . . she ends up sitting at a cafe in Manhattan during the Chitauri invasion, where she meets Captain America and causes headaches for Fury and serious tech envy for Tony):
http://kris-oldfic.livejournal.com/53290.html Big Bang Theory/Gilmore Girls:
--"Towel Day" by Keiko Noriko (cute one-shot set pre-series for TBBT and sometime after Jess goes out to California to get to know his dad and starts to bond with his sort-of step-sister Lily over the joys of reading Douglas Adams):
http://www.fanfiction.net/s/6859084/1/Towel-Day Big Bang Theory/Harry Potter:
--"Mortal Goddess" by Scifichick774 (cute one-shot in which Sheldon discovers that his favorite comic book goddess might actually exist):
http://kris-fic.livejournal.com/81683.html Castle/Captain America/Iron Man:
--
Rogers 'verse SERIES by
faithburke/PaBurke (set after Iron Man 2 and Captain America, but before The Avengers, and at least mid-series for Castle; Steve Rogers discovers that his romance with Peggy Carter has left him with a surprise legacy -- a 69-year-old daughter who adopted his name as her stage name -- and he turns to Pepper Potts and Tony Stark for help in learning more about Martha Rogers and the rest of his new-found family; a series of short fics):
http://archiveofourown.org/series/119790 1) "Rogers Do Things the Hard Way":
http://faithburke.livejournal.com/72411.html or
http://archiveofourown.org/works/18608252) "Rogers Do It By the Book":
http://faithburke.livejournal.com/73696.html or
http://archiveofourown.org/works/18608403) "Rogers Do What They Do and Shut Up About It":
http://faithburke.livejournal.com/90932.html or
http://archiveofourown.org/works/18608794) "Rogers Take Care of Their Friends" (White Collar cross):
http://faithburke.livejournal.com/108388.html or
http://archiveofourown.org/works/18609425) "(Rogers)Fight for Home" (Joan of Arcadia/Supernatural/Dresden Files cross):
http://faithburke.livejournal.com/109018.html or
http://archiveofourown.org/works/1860810?view_adult=true6) "Rogers Sneak Up on You":
http://faithburke.livejournal.com/109988.html or
http://archiveofourown.org/works/18609967) "Rogers Family Secrets":
http://archiveofourown.org/works/1984968 Chuck/Firefly:
--
"Casey vs. The Family Tree, or Jayne Meets the Parents" by
goddessofbirth (Chuck/Sarah, and eventually River/Jayne, John/Ellie; post-BDM, Jayne and River find themselves stranded on early 21st century Earth and in desperate need of help from the Intersect, but why is Jayne Cobb such a dead ringer for John Casey?):
http://goddessofbirth.livejournal.com/19203.html [prologue] to
http://goddessofbirth.livejournal.com/46325.html [ch. 16]
http://goddessofbirth.livejournal.com/48980.html [ch. 17] (see
http://web.archive.org/web/20100910014001/http://goddessofbirth.livejournal.com:80/48980.html)
http://goddessofbirth.livejournal.com/51801.html [ch. 18]
http://goddessofbirth.livejournal.com/54012.html [ch. 19]
http://goddessofbirth.livejournal.com/56838.html [ch. 20]
http://goddessofbirth.livejournal.com/60930.html [ch. 21]
http://goddessofbirth.livejournal.com/62157.html [ch. 22]
http://goddessofbirth.livejournal.com/173608.html [ch. 23]
http://goddessofbirth.livejournal.com/92557.html [ch. 24]
http://goddessofbirth.livejournal.com/97520.html [ch. 25]
http://goddessofbirth.livejournal.com/105073.html [ch. 26]
http://goddessofbirth.livejournal.com/118530.html [ch. 27]
http://goddessofbirth.livejournal.com/129581.html [ch. 28]
http://goddessofbirth.livejournal.com/136152.html [ch. 29]
http://goddessofbirth.livejournal.com/145495.html [ch. 30]
http://goddessofbirth.livejournal.com/153590.html [ch. 31]
http://goddessofbirth.livejournal.com/162085.html [ch. 32]
http://goddessofbirth.livejournal.com/174540.html [ch. 33]
http://goddessofbirth.livejournal.com/182941.html [ch. 34]
http://goddessofbirth.livejournal.com/186094.html [ch. 35]
http://goddessofbirth.livejournal.com/189545.html [ch. 36]
http://goddessofbirth.livejournal.com/197710.html [ch. 37]
http://goddessofbirth.livejournal.com/198323.html [ch. 38]
http://goddessofbirth.livejournal.com/212361.html [ch. 39]
http://goddessofbirth.livejournal.com/214298.html [epilogue]
(see also the two follow-up short fics "The Heart of the Matter" and "Christening" at
http://goddessofbirth.livejournal.com/tag/cvtftojmtp)
Dresden Files/Star Trek (2009):
--"Sufficiently Advanced Magic" SERIES by
jedibuttercup; (post-2009 movie, Kirk, Spock, and Scotty chase a time-travelling criminal to the San Francisco of Harry Dresden's time and discover that they need the Wardens' help to deal with the magical nature of the threat to their future; in the sequel, Dresden's very long lifespan allows him to meet young Kirk and his bridge crew again, in their own time, and show them that magic still exists in their world):
http://archiveofourown.org/series/181037; or see the separate stories at
http://jedibuttercup.dreamwidth.org/5202.html and
http://wishlist-fic.livejournal.com/129319.html or
1) The Only Logical Conclusion,
2) Is There a Problem, Officer?,
3) Tying up the Loose Ends,
4) Per Aspera Ad Futurum Firefly/Anita Blake:
--"Different Eyes" by
mhalachai; (one month post-OiS, an immortal Anita Blake and her strange family take passage on Serenity in an attempt to get home):
http://www.tthfanfic.org/Story-7462/Mhalachai+Different+Eyes.htm or
http://archiveofourown.org/works/323641/chapters/521225 Firefly/Avengers (2012):
--"Some Hero" by fringeperson (Loki owes Clint big for all the stuff he did -- including more than just mental violation -- so as restitution/part of his punishment, Loki offers Clint [who was fired by SHIELD as being compromised and easily replaceable after the battle of New York] a place where he'll be appreciated, even though it'll be in the distant future far from earth-that-is/was; with his own ingenuity and resources, plus a few parting gifts from Tony Stark including a portable copy of JARVIS and a small arc reactor, Clint sets out to join 'Serenity' right at the beginning of the TV series and stays through the end of the BDM, helping Kaylee and River greatly, and finally starting to heal for himself; now, if only Loki wasn't so determined to help and win him 'back' some day . . .):
https://www.fanfiction.net/s/9016177/1/Some-Hero --"The Last Firefly of the Season" by fringeperson; (River Tam, Winter Soldier/Bucky Barnes; at the Academy River is instructed in combat -- and dancing! -- by the defrosted warrior she is told to call only "Soldier", but they bond and then break out together eventually, finding passage aboard a Firefly vessel):
https://www.fanfiction.net/s/11514475/1/The-Last-Firefly-of-the-Season --"It Seems to be Powered by Some Sort of Electricity" by
jedibuttercup; (post-BDM one-shot for Firefly 'verse, with AU twist to the end of The Avengers -- Tony's return journey through the portal lands him on Serenity, instead of back in NYC):
http://wishlist-fic.livejournal.com/93250.html or
http://archiveofourown.org/works/590649 or
http://www.tthfanfic.org/Story-28575-11/jedibuttercup+A+Wish+a+Day+Keeps+the+Mayan+Apocalypse+Away.htm Firefly/Battlestar Galactica (2003):
--"Out of the Black" by
rayruz/hazellazer; (goes AU for BSG at the end of season 3, when the Colonial Fleet comes across pre-BDM Serenity just before their intended jump to Earth; learning about "Earth-that-was" and the Unification war from Mal's crew, the Colonials and allied Cylons decide to try to settle quietly on some Alliance worlds, trying to avoid official notice; unfortunately, the fleet's troubles are far from over; Kaylee/Tyrol, among other pairings):
http://archiveofourown.org/works/72054/chapters/95418 or
http://tulipfic.livejournal.com/tag/!series:%20out%20of%20the%20black Firefly/Being Human:
--"Wolves in the Black" by
dharkapparition (George has lost Nina and Mitchell in the unification war, and finds a new family when he becomes 'Serenity's new pilot, post-BDM; BtVS' Oz has a cameo appearance in flashback):
https://xover-exchange.livejournal.com/16841.html Firefly/Big Bang Theory:
--"100 Ways to Kill a Doctor: Reaver Equalizer" by Shenandoah76209 (part of a collection of challenge fics, in which Leonard and/or Amy is killed, each about 1500 words; Sheldon and Penny end up joining the crew of 'Serenity'):
https://www.fanfiction.net/s/11579541/1/100-Ways-To-Kill-a-Doctor-Reaver-Equalizer --"100 Ways to Kill a Doctor: Hands of Blue Execution" by Shenandoah76209 (potential Sheldon/Penny and River/Jayne; Sheldon is Jayne's cousin as well as River's fellow escapee from the Academy):
https://www.fanfiction.net/s/11587273/1/100-Ways-To-Kill-a-Doctor-Hands-of-Blue-Execution --"100 Ways to Kill a Doctor: I'd Rather They Were Witches" by Shenandoah76209 (Sheldon/Penny, River/Jayne):
https://www.fanfiction.net/s/11587437/1/100-Ways-To-Kill-a-Doctor-I-d-Rather-They-Were-Witches --"100 Ways to Kill a Doctor: Fuel Efficiency" by Shenandoah76209 (Sheldon/Penny and River/Jayne; Sheldon is Jayne's cousin and captain of his own ship, called on for help during "Out of Gas"):
https://www.fanfiction.net/s/11588090/1/100-Ways-To-Kill-a-Doctor-Fuel-Efficiency --"100 Ways to Kill a Doctor: Shindig Conundrum" by Shenandoah76209 (Sheldon/Penny and River/Jayne attend yet another fancy ball, and Mal fears for the worst):
https://www.fanfiction.net/s/11588971/1/100-Ways-To-Kill-a-Doctor-Shindig-Conundrum --"100 Ways to Kill a Doctor: Lightening Revelation" by Shenandoah76209 (potential Sheldon/Penny; Penny and Sheldon are both related to Jayne, but not to each other):
https://www.fanfiction.net/s/11589322/1/100-Ways-To-Kill-a-Doctor-Lightening-Revelation WIP--"The Space Angel Angle" by
faythbrady/Fayth3 (potential Sheldon/Penny; one of Sheldon's inventions strands himself and Penny in the distant future, where their only hope of getting home depends on Mal and his crew; not updated since 2011, but still enjoyable):
https://www.fanfiction.net/s/5893938/1/The-Space-Angel-Angle (but see her LJ for chapter 11, never cross-posted to ff.net:
http://faythbrady.livejournal.com/tag/sheldonpenny)
Firefly/BtVS link Firefly/Chronicles of Riddick/Pitch Black/Riddick:
--"All the Voices Never Stop" by Shenandoah76209 (River/Riddick; goes AU during "Our Mrs. Reynolds, with River acquiring herself a willing husband with strange eyes):
https://www.fanfiction.net/s/10069453/1/All-the-Voices-Never-Stop (See also a lengthy one-shot giving River's POV on their story, "All of Me":
https://www.fanfiction.net/s/11663204/1/All-Of-Me)
--"Break the Civilized Chains" by Shenandoah76209 (River & Riddick; the sleazier mercs who arrive on Not-Furya during the movie "Riddick" have already taken and abused River for far too long; together, the two 'captives' may turn out to be even more lethal):
https://www.fanfiction.net/s/9773193/1/Break-the-Civilized-Chains (Author has another completed River/Riddick series I've not yet read:
Invictus in the Black and its sequel
The Ghost & The Darkness)
--"There Your Treasure Lies" by
jedibuttercup (River/Riddick, post-Serenity and post-Riddick; one-shot, for now):
http://www.tthfanfic.org/Story-30858-2/jedibuttercup+A+Plate+of+Crispy+Wishes.htm --"
The Spiral-'verse" SERIES by
goddessofbirth (starts out River/Riddick but quickly turns into Jayne/River/Riddick OT3, with Vaako/OFC on the side; seeking a safe place to bury Jack/Kyra's remains, Riddick's Necro ship and crew fall prey to Reavers in a strange corner of the galaxy, but Riddick himself is rescued by River and the rest of the post-BDM crew of Serenity, while Lord Vaako sets out in another ship in search of the missing Lord Marshall Riddick):
0.a) "Emiline" (35-40 years pre-Chronicles of Riddick)
http://goddessofbirth.livejournal.com/154425.html0.b) "The Jully" (Lord Vaako's back-story)
http://goddessofbirth.livejournal.com/152407.html0.c) "Something Else" (Lord Vaako's back-story, 10-15 years before Chronicles of Riddick)
http://goddessofbirth.livejournal.com/181066.html 1) "Doppleganger" (River/Riddick)
http://prozacandcandy.livejournal.com/5512.html2) "The Claiming" (River/Riddick)
http://prozacandcandy.livejournal.com/5697.html3) "Sensory" (established River/Riddick, pre-Rayne, NC-17)
http://goddessofbirth.livejournal.com/172162.html 4) "Fate" (River/Riddick, with pre-Rayne and pre-Jayne/River/Riddick, 19 out of 20 chapters completed):
1/20
http://goddessofbirth.livejournal.com/133076.html2/20
http://goddessofbirth.livejournal.com/136844.html3/20
http://goddessofbirth.livejournal.com/143392.html4/20
http://goddessofbirth.livejournal.com/149800.html5/20
http://goddessofbirth.livejournal.com/160732.html6/20
http://goddessofbirth.livejournal.com/166022.html7/20
http://goddessofbirth.livejournal.com/178629.html8/20
http://goddessofbirth.livejournal.com/185068.html9/20
http://goddessofbirth.livejournal.com/187229.html10/20
http://goddessofbirth.livejournal.com/193039.html 11/20
http://goddessofbirth.livejournal.com/204603.html12/20
http://goddessofbirth.livejournal.com/208526.html13/20
http://goddessofbirth.livejournal.com/223045.html14/20
http://goddessofbirth.livejournal.com/223939.html15/20
http://goddessofbirth.livejournal.com/224303.html16/20
http://goddessofbirth.livejournal.com/225457.html17/20
http://goddessofbirth.livejournal.com/226621.html18/20
http://goddessofbirth.livejournal.com/231084.html19/20
http://goddessofbirth.livejournal.com/236248.html20/20 _________________________________________________
5) "The Regent" (Lord & Lady Vaako)
http://goddessofbirth.livejournal.com/108882.html 6) "Secure" (River/Jayne, implied River/Jayne/Riddick, NC-17)
http://goddessofbirth.livejournal.com/148729.html7) "Transition" (established River/Jayne/Riddick, NC-17)
http://goddessofbirth.livejournal.com/173099.html8) "Fluid" (established River/Jayne/Riddick, NC-17)
http://prozacandcandy.livejournal.com/18819.html9) "After Party" (established River/Jayne/Riddick, NC-17)
http://goddessofbirth.livejournal.com/128427.html10) "Stakes" (Riddick/Jayne, rated M)
http://goddessofbirth.livejournal.com/218689.html11) "Everyday Ordinary" (established River/Jayne/Riddick)
http://goddessofbirth.livejournal.com/76050.html12) "Clubbing" (established River/Jayne/Riddick)
http://goddessofbirth.livejournal.com/78146.html13) "The Pen" (established River/Jayne/Riddick, fluff)
http://goddessofbirth.livejournal.com/123929.html14) "Control" (established River/Jayne/Riddick, NC-17)
http://goddessofbirth.livejournal.com/151031.html15) "Conversation" (established River/Jayne/Riddick)
http://goddessofbirth.livejournal.com/80469.html16) "Ingredients" (established River/Jayne/Riddick, NC-17)
http://goddessofbirth.livejournal.com/141421.html 17) "Water" (pre-Vaako/Sade)
http://goddessofbirth.livejournal.com/178975.html18) "Fire" (Vaako/Sade)
http://goddessofbirth.livejournal.com/194835.html19) "Flint and Tinder" (Vaako/Sade)
http://goddessofbirth.livejournal.com/200330.html 20) "Weaves" (Riddick/Jayne, rated M)
http://goddessofbirth.livejournal.com/181530.html 21) "Peace" (Vaako/Sade)
http://goddessofbirth.livejournal.com/195455.html22) "Earth" (Vaako/Sade)
http://goddessofbirth.livejournal.com/154053.html23) "Air" (Vaako/Sade, rated M)
http://goddessofbirth.livejournal.com/196906.html24) "Carving Out" (Vaako/Sade)
http://goddessofbirth.livejournal.com/207524.html 25) "Rescue" (Jayne/River/Riddick future!fic, set 10 years after "Doppleganger")
1/3
http://goddessofbirth.livejournal.com/158532.html2/3
http://goddessofbirth.livejournal.com/158978.html3/3
http://goddessofbirth.livejournal.com/159910.htmlEpilogue
http://goddessofbirth.livejournal.com/160122.html 26) "On the 15th of May" (Jayne/River/Riddick)
http://goddessofbirth.livejournal.com/168956.html27) "First Night" (Jayne and Riddick and their kids)
http://goddessofbirth.livejournal.com/197600.html28) "Gathering" (Vaako/Sade)
http://goddessofbirth.livejournal.com/245736.html29) "Two Cities" (Vaako/Saade)
http://goddessofbirth.livejournal.com/210361.html Firefly/Chuck/X-Files:
--"A Mercenary's Tale" by
vandevere (eventual River/Jayne; Goes AU from Firefly canon after the episode "Trash", when it turns out that Jayne is actually a lot younger than he thinks, being the clone of long-dead Colonel John Casey, intended to carry on Casey's fight against alien invaders; this story is actually a sequel to a Chuck/X-Files fic that I haven't yet read, but this tale can be read and enjoyed just fine on its own):
http://www.fanfiction.net/s/6120313/1/A-Mercenary-s-Tale Firefly/Farscape:
--"Mama Bears" SERIES by Tassos (Another deal has gone sour for Mal, but a pair of rather interesting locals are willing to trade gun-slinging skills for medical help with their young son; Aeryn/Crichton):
http://archiveofourown.org/series/13229