A hapless UN employee discovers that the agency he works for is hiding a gateway to a parallel dimension that's in a cold war with our own, and where his other self is a top spy. The war slowly heats up thanks to spies from both sides.

In 1943, in Los Alamos, New Mexico, a team of government scientists is working on the top secret Manhattan Project in a race to produce an atomic bomb before the Nazis. Meanwhile, their families adjust to a life on the military base.

Susan returns to England, where she investigates a mystery involving a children's author's death, connected to a 1955 story set in Corfu.

The orphan Pip becomes a gentleman when his life is transformed by a mystery benefactor.

Art historians discuss Pablo Picasso's early years as an artist and his early works.

After 5 years of fighting in the crusades, Robin returns to England and leads a band of outlaws to outwit the Sheriff of Nottingham.

Explosive events unfold after Wright family patriarch Jack is discovered dead from a supposed suicide, leaving his immediate family utterly devastated.