It's now the winter of 1941 and Lewis Eliot is among a group that establishes Mr. Toad, the British Atomic Energy Establishment. Lewis' role is primarily to recruit the atomic scientists they will need. His brother Martin Eliot is one of the scientists who would like to get in on the project. His other task is to choose between two scientific factions and recommend to the Minister which should be tasked with developing the bomb. He also meets Margaret Davidson, the daughter of a well-known art critic who works at the Treasury. They are instantly attracted to one another and are soon lovers. She's hesitant to marry him however. Roy Calvert meanwhile has signed up to become a bomber pilot and is also hoping to marry Rosalind Wykes.