Sergeant Daniels is a character the player encounters during the course of the Mothership Zeta DLC. He was part of Elliot Tercorien's squad during the U.S. Anchorage campaign against the Chinese communist invaders. Daniels, along with Tercorien and Private Beckett were abducted while investigating a call for aid by one of their fellow squad-mates.
After being abducted, Daniels was placed in cryo-sleep, along with Beckett. During the Among the Stars quest, the player can revive both Daniels and Beckett if the player has Elliot in your party. The player must first allow Elliot to restore his memory or else he will engage Private Beckett in a fight to the death.