To defeat this new threat you'll have to perform overkill effects or be prepared to be overwhelmed by rapidly deploying enemy fleets. The Endless feed off each other and the more of them on the board, the more dangerous they become. Lucky for you, we've got ship upgrades available to help you overcome this radical new threat. 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.