First off, this movie is fantastic. This is one of those rare movies that I resist watching for the longest time under the smug pretext that I already know what it's about and won't like it — then end up watching and absolutely love.
Two American backpackers are assaulted by a werewolf in northern England. One dies, the other wakes up in a hospital bed in London, and starts to fear that on the next full moon he'll turn into a werewolf and perpetuate the carnage.
I don't like horror movies. This isn't one. It's funny from start to finish, with beautiful shots of the early eighties, likeable actors and a narration that never goes over the top, which it would have in the hands of most comedy directors.
What the movie doesn't have is the Warren Zevon song or Michael Jackson, who asked Landis to direct the Thriller video (1983). It's not a laugh-out-loud movie, but I sure grinned and chuckled a lot. If you haven't yet seen this, do yourself a favor and drop everything on your "to watch" list. It's a real gem.