Every year, the BBC holds the annual Children in Need telethon — an appeal to raise money for children's charities in the UK — and every year, a number of British celebrities and television shows take part, and the BBC's favorite and longest running sci-fi show, Doctor Who, often makes a guest appearance with a mini-episode bridging the last season with the forthcoming one.

For the 2007 Children in Need telethon, Doctor Who did something a bit different and decided to have the Tenth Doctor, played by David Tennant, run smack into the Fifth Doctor, played by Peter Davidson. The resulting mini-episode is now up on YouTube for everyone to enjoy, and what it lacks in logic or plausibility, it really makes up for by dint of the Doctors' collective charm.

I really like it. Peter Davison is about fifty pounds too heavy and twenty years too old for the role, but he's still a great Doctor, and I love the teasing rapport David Tennant has with him ("Not a lot of men can carry off a decorative vegetable."). Steven Moffat wrote the episode, and he's probably the best of the current Doctor Who writers: he wisely alludes to Davison's changed appearance, but doesn't bother explaining it, which is just as well, since any explanation would doubtlessly be pretty weak.

I even got a bit teary at the end, when the Tenth Doctor tells the Fifth that he was always trying to be old and grumpy to seem important, and that turning into the Fifth Doctor was what really changed him into a younger and more fun-loving Doctor. Peter Davison was always one of my favorite Doctors, and it's always depressed me he spent his entire run in the shadow of Tom Baker's greatness, when he was really just as good.

I think this may be the single best thing to come out of the relaunched Doctor Who. Bravo, guys.

Doctor Who, Children in Need Special - Time Crash [YouTube]