The Sub Terra core box is required to play this expansion.

You are completely overwhelmed!

The nightmares of these caverns must be eradicated at all costs. Aided by the sinister Exterminator, transport powerful explosives to structural weak points in the caves, then escape before the final detonation. It's not going to be easy!

Annihilation introduces a whole new way to play the game. Push deeper into the cave to reach structural weak points, plant powerful bombs, then return to the exit before they explode. The Exterminator can prevent horrors from spawning and is immune to gas, which helps you keep your escape routes open while you complete your mission. It's not going to be easy.