Based on true events, an American submarine collides into a Soviet sub of the coast of America and an ensuing standoff occurs that could lead to total annihilation.

This series shows the workings of an English hospital through the eyes of its junior doctors. Naive and idealistic Dr Andrew Collins (Andrew Lancel), soon realises he still has much to learn. His boss, Dr Claire Maitland (Helen Baxendale) on the other hand, has seen it all. She is a competent doctor, with a cynical view, and is ready to work the system when needed, but she and Collins work well together as she guides him through the many minefields of working in the NHS.

Assigned to oversee the development of the atomic bomb, Gen. Leslie Groves is a stern military man determined to have the project go according to plan. He selects J. Robert Oppenheimer as the key scientist on the top-secret operation, but the two men clash fiercely on a number of issues. Despite their frequent conflicts, Groves and Oppenheimer ultimately push ahead with two bomb designs — the bigger "Fat Man" and the more streamlined "Little Boy."

During a long, hot summer on the Thamesmead Estate in Southeast London, three teenagers edge towards adulthood.