We've finished with the canonical Marathon Trilogy and are moving on to third party scenarios, starting with EVIL. In this scenario, a UESC ship from Tau Ceti runs into a spatial anomaly that sends them far away where we encounter something dark and evil.
Last time, we used co-op to cheat our way through a moving platform puzzle. This time, Narcogen negotiates a sewer maze looking for buttons while Blackstar fights respawning enemies.
EVIL can be played, like the other Marathon games, using the open source Aleph One engine which you can get here for Windows, Mac and Linux: