Returning to Little Paddocks, Craddock tells Miss Blacklock that Scherz was a petty thief who came to England with forged papers to evade the Swiss police. Miss Blacklock insists that she cannot think of anyone who wants to kill her.

Craddock questions Mitzi again. She remains adamant that she locked the front door on the day of the shooting and suggests that Phillipa is lying about locking the side door. Mitzi claims that on the day Scherz came to Little Paddocks asking Miss Blacklock for money, she heard Phillipa talking to Scherz in the summerhouse.

After interviewing Mitzi, Craddock tries to open the dummy door instead of the main drawing-room door. Dora points out his mistake and mentions that there was a table against the unused door until about a fortnight ago. She reveals that the door works but is locked and bolted and has not been used for years. When Craddock tries the bolt, it slides open easily. He finds the key to the lock in a drawer, and the door opens smoothly without making a sound. Craddock tells Dora the lock and hinges of the door have recently been oiled.