The big bosses over at Channel 4 have already given the green light for another six episodes of Ricky Gervais' Derek, but before we get ahead of ourselves, we've got series one to finish off first. It's a difficult day for the retirement home as one of the residents falls gravely ill in tonight's series finale. The staff have to pull together and prepare themselves and the rest of their charges for the worst. And as if that wasn't bad enough, things get rather complicated for Derek when an unexpected visitor comes calling.