 As Gears of War 2 begins, the COG army is mobilizing to send forces into the depths of Sera to assault the Locust directly. The COG deploy several units into the Locust Tunnels, known as'The Hollow', despite sustaining heavy casualties. Delta Squad, consisting of Marcus Fenix, Dom Santiago, Benjamin Carmine and later Augustus Cole and Damon Baird, continues to search the Hollow and discovers that the Locust are using a giant Riftworm to sink the human occupied cities. The Locust plan to destroy the rock structures at the outskirts of Jacinto, the last major Human city, in hopes of sinking it into the ground.
