Episode 7 of the renewed Spartan Ops season for Halo 4 debuts on Monday, and a per usual, Microsoft has unveiled a teaser for the five-mission co-op package. In this go round, embattled scientist Catherine Halsey gets a bit of payback for her current house arrest.

This series is entitled Invasion, and shows the UNSC Infinity being invaded by Promethean Knights, while Halsey appears to collaborate with Covenant bad guy Jul 'Mdama in their hunt for the Librarian. The episodes seem to be getting darker and darker.

Also coming next week for multiplayer will be a Grifball playlist, as well as two new specializations, Engineer and Stalker.