FOUND! Someone in another group let me know it’s just been posted on AO3:
https://archiveofourown.org/works/61283185 I feel like I’ve lost my mind! I have a clear memory of starting a Sentinel/NCIS/Criminal Minds crossover fic named “Fragile,” and I feel like it was this year, 2024.
It was a twist on the fragile guide theme where Tony DiNozzo (NCIS) was hiding that he was a Sentinel but had lost the Sentinel abilities because of his protection of his “fragile” Guide, who was an original character. Tony was sent to the BAU (Criminal Minds) to work a case, and somehow it had to do with what happened to his Guide in the past, the events that made the Guide fragile. I can’t remember the Guide’s name or even if that had come out yet in the parts that I had read.
I think the author had “vvc” in the name but I’ve searched with that and haven’t found it, so I may be wrong.
It was amazingly well-written and I was thoroughly enjoying it. It was being posted one chapter at a time, so I never got to the last chapter to see how it all ended up, and now I can’t find it anywhere, and I just cannot remember where I was reading it.
Does it sound familiar to anyone? Thanks in advance for your help!