It remains to be seen if 'Community' will swing back into critical favor after last week's "Conventions of Space and Time" failed to win over critics, but there can be no doubt that the impressive list of season 4 guest stars have been fun to watch already. Whereas last week featured a brief turn from 'Battlestar Galactica's Tricia Helfer and 'Bridesmaids' star Matt Lucas, this week's "Alternative History of the German Invasion" will introduce Malcolm McDowell as history teacher Professor Cornwallis! Get a sneak peek of McDowell's first 'Community' appearance inside!

'Community' has featured some incredible guest stars in its day, but perhaps none so iconic as one-time 'A Clockwork Orange' star Malcolm McDowell as the gang's new history professor Noel Cornwallis! NBC and HuffPostTV have released a new clip from the episode highlighting Cornwallis' first appearance, in which the man reveals his less-than-studious reasons for transferring from Oxford.

Elsewhere, the episode also features recent 'The Office' and upcoming 'Arrested Development' star Chris Diamantopoulos as the new leader of Greendale's gang of obnoxious Germans, following 'The League' star Nick Kroll's exit. Will Malcolm McDowell be able to keep the group in line, or will those dastardly Germans invade too far?

Get of sneak peek of this week's 'Community' episode "Alternative History of the German Invasion" below, and give us your predictions in the comments!

More From ScreenCrush