I think I've mentioned this before, but To Say Nothing of the Dog is a fine book to use as a guide when setting up some rules of time-travel.

The item that I am stealing for this episode is the idea that sometimes the timestream doesn't let you get close to where you want to go.

Also, apropos of nothing, this magic trick is neat.

--Geoff

So, Peter managed to win himself an army by blowing his cover while fighting a robot beaver, but the other FOUR members of the team, through diligent detective-work and the use of inexplicable time-bending powers, have come up without so much as a sausage to fight the Thoremerson with, it would seem. Unfettered violence is SO always the best solution...

- Count Dolby von Luckner