Because I'm going to watch the last episode of Doctor Who series 2 tonight! And because I like the idea of Archie travelling with the Doctor and Horatio being jealous of the Time Lord because Archie has so much fun with him, and traumatised by the "nakedness" of Rose, heh.
1. Lieutenant Bush is the eighth Doctor.
2. Napoleon is a big green farting evil alien in disguise, and he's going to destroy the world (London in particular, because all evil aliens LOVE to blow up London)! Now we need the Doctor!
3. In Retribution, after Archie says "Better already!" and Horatio (finally) says "My dear friend", Archie regenerates into, well, any white male, while Horatio freaks out.
4. Pellew is a Time Lord. The Indefatigable is his TARDIS. That's how the Indy (and Pellew himself) contrive to always appear in the right place at the right time whenever Horatio is in trouble.
5.
Archie: Please take what I offer. Just take it and say goodbye.
Horatio: Archie ... I'm honoured to have served with - WHAT'S THAT!!??
(TARDIS materialises in the infirmary. The Doctor - Ninth or Tenth - and Rose walk out.)
Doctor: (cheerfully) Hello there!
Rose: Doctor, I think we've got wrong time and place wrong again...
Horatio: Who are you, sir!?
Doctor: I'm the Doctor!
Horatio: You're a doctor? Please, please help my friend... (in tears)
Archie: ...
(The Doctor takes them all into the TARDIS and Archie is saved in some distant planet. Or he takes him to Dr Stephen Maturin. Rose goes "Awww" because she thinks Archie and Horatio are romantic. And everyone lives happily ever after!)