54 new cards including external threats, internal threats, ship upgrades, and a new final encounter.
Replacement Ouroboros cards to bring the 1st edition inline with the 2nd printing.
Note: You do not mix this new expansion with the base game cards. This new mini-expansion plays on its own but requires the base game. However, the upgrades can be used with the original threat deck. Fully compatible with all 4 ships. Yes, it fits in the base game box.