In modern times, when Bucky returned to the abandoned HYDRA base, he saw a Sleeper. More of them attacked Hydro-Base and freed the Red Skull. Bucky managed to destory a Sleeper when Captain America and Nick Fury were hunting for him.
Later, in Washington, D.C., several Sleepers combined themselves into one giant Mega-Sleeper with a Nova Cannon in its chest. The Avengers fought the Mega-Sleeper until Captain America and Winter Soldier arrived to target the CPU in its head. Captain America and Winter Soldier found Red Skull in the CPU part of the Mega-Sleeper where Red Skull planed to brainwash them to serve him. Winter Soldier then broke free as the fight within the Mega-Sleeper damaged the giant machine. The Avengers managed to cause the Mega-Sleeper to collapse into the clearing.