Loyalty and Friendship

Leithen's motivation to investigate Pitt-Heron's disappearance stems from his loyalty to his friend Tommy Deloraine and his sympathy for Pitt-Heron's wife, and he later relies on allies like Chapman and Felix to survive.

Leithen recruits Chapman out of friendship for Tommy and Pitt-Heron, and Chapman's loyalty is unwavering.

Chapman's decisive rescue of Leithen, based on loyalty and quick thinking, underscores the bond between them.

The narrator protects Pitt-Heron's secret and arranges his return; Tommy's loyalty is evident in his adventures and his trust in the narrator.