Over the past season, Community has done a fantastic job of incorporating TV stereotypes into their show by attacking their ridiculousness and then using them to their advantage. Last night was a "bottle episode" and things got intense. Also, naked.

The set-up: Annie has lost her gel pen and believes that someone in the study group took it. Things get progressively crazier as the episode goes on, but begins with searches of everybody's bags. Inside Abed's bag? A chart of the girls menstural cycles. Don't worry, it's not as crazy as it sounds — or is it?

Shirley refused to hand over her bag until they took it from her. What was inside?

Community's "Bottle Episode" Strips Entire Cast Down to Their SkivviesS

A gloriously-named pregnancy test. Abed's knowledge of the girls' cycles made it so he could pinpoint the night on conception — Halloween. Which, if you'll recall, is the night she and Sr. Chang hooked up.

With the addition of Theo Huxtable as Shirley's ex-husband joining the show soon, expect for this to become an important storyline.

Finally, the group decides to get down to their underwear to prove that none of them has the pen. Cue the naked, attractive bodies!

Eventually, the group decides to give it a rest and blame it all on a ghost. The truth actually wasn't so far off...

Update: Brilliant! Bill so kindly pointed out that you can see the pen being stolen in the beginning:

Community's "Bottle Episode" Strips Entire Cast Down to Their SkivviesS