A young American researcher at the British Museum who assists Grant with his investigation, sharing a passion for uncovering historical truths.

A flamboyant London stage actress and friend of Grant's who helps keep his mind active during his hospital stay by encouraging his detective work.

Grant’s dowdy landlady, formerly a theater dresser, who is fascinated by theatrical personalities like Marta.

A colleague of Grant's from Scotland Yard, known for his kind heart and literal-mindedness, who provides Grant with updates and support.

A petite and strong nurse who efficiently manages Grant's care, exhibiting a straightforward and no-nonsense demeanor.

A tall and sentimental nurse who tends to offer unsolicited comfort to her patients, which Grant finds aggravating.

A composed and thoughtful head of nursing who makes brief visits to Grant, offering valued insights into his historical investigation.

A medical professional overseeing Grant's recovery, who shows limited interest in history but provides an unusual perspective on a historical figure's appearance.