Legends of Tomorrow season 2 episode 1
Episode title: Out of Time
Dr. Nate Heywood, an unconventional historian, makes a shocking discovery. Nate then seeks out Oliver Queen for help to find the scattered Legends. Once reunited, they try to protect Albert Einstein from being kidnapped before the Nazis destroy New York City with a nuclear bomb. Meanwhile, Ray notices that Sara has a mission of her own, which leads them both to face her nemesis, Damien Darhk.
