"There's a mole. Right at the tippy top of The Circus..."

If you haven't spent at least 5 minutes this year pretending to be the slippery Simon McBurney, you're probably more normal than me. But his undersecretary Oliver Lacon is just one of the cast members who relish the enigmatic dialogue of Peter Straughan (The Debt, The Men Who Stare at Goats) and Bridget O'Connor's winding adaptation of John le Carré's seminal novel.

It's hard to follow for many - the beginning is way too jumpy - but combined with Tomas Alfredson's impeccable visuals, this slow-burn story of betrayal and decay is a sumptuous bit of cinema (here's our Tinker Tailor Soldier Spy review). Which is why the Tinker Tailor Soldier Screenplay makes the Christmas reading list in our Advent Calendar this week.

For those who appreciate Gary Oldman's almost total lack of speech, but want to memorise his electrifying monologue about Russian gangster Karla, it's perfect material for post-Boxing Day lunch. And for those sleepy relatives who still don't understand who the mole was, this streamlined version of the book is great for brief recaps - or just hitting them over the head with.

Thanks to Focus Features and their sexy awards campaign, you can download it for yourself. To read the Tinker Tailor Soldier Screenplay, head this way.