One day in the spring of 1941, Kay Bryant walked along a bombed London street in which she had rented a room before the war. She had come to see what the blitz had done to Little Carberry Street, and now that No. 10 had vanished completely, there was a chance she might be able to forget some of the horror associated with the house, and at last blot out its grim memories of murder. It all began when a gun was found hidden under the floorboards – a gun which had been used in the murder of the room's previous occupant. The police were convinced that the murderer would be found among the inhabitants of No. 10, yet to Kay this seemed impossible, for all of them were her friends. At the time, each of them appeared to think it was someone else, and there was a case for any of them to have done it. But one of them knew too much, and a further death took place. In present day, reunited with Inspector Cory among the ruins, Kay vividly relived those days of suspicion. For she knew one thing the other tenants didn't. Did Inspector Cory know it too?