Alan Grant is an inspector with Scotland Yard who struggles with physical and mental restlessness during his forced confinement in the hospital. He possesses a unique talent for discerning a person's character simply by studying their face. Disgusted by formulaic novels, he turns his sharp deductive mind toward an unsolved historical mystery to stave off his severe boredom.

Brent Carradine is a young American researcher working at the British Museum. He is staying in London to be near his actress girlfriend and to avoid joining his father's furniture business in America. Energetic and enthusiastic, he delights in digging up primary documents and investigating historical records to help Grant uncover the facts behind the history books.

Richard the Third is a 15th-century English monarch widely remembered in history books as a monstrous villain who murdered his nephews to secure the throne. When Grant studies his portrait, he sees a man of conscience rather than a criminal, sparking his comprehensive investigation into the king's true character and actions.

Henry the Seventh is the first Tudor king, known historically as Henry Tudor. As Grant digs into the history of the royal succession, he begins to examine Henry's actions, motives, and character during his early reign to compare them against Richard's record.

Marta is a glamorous and flamboyant London stage actress who maintains a close friendship with Grant. She brings him a folder of historical portraits, inadvertently sparking his obsession with Richard the Third. She also connects him with a researcher to assist his bedside investigation.

Mrs. Tinker is Grant's dowdy but devoted landlady. She is highly thrifty, refusing to use the expensive purses Grant gifts her, and prefers wearing an old blue hat for special occasions. She is somewhat awe-struck by theatrical personalities.

Sergeant Williams is a large, stolid young police officer who works alongside Grant at the Yard. Though he lacks Grant's vivid imagination and doesn't fully grasp the nuances of the historical investigation, he is good-hearted. He cheerfully fetches history books for his bedridden colleague.

Nurse Ingham is a petite but strong nurse who cares for Grant during his recuperation. Grant privately nicknames her The Midget because she manages her six-foot-tall patient with physical ease. She shows no interest in his historical quest and quickly dismisses his theories based on her preconceived notions of history.

Nurse Darroll is a tall, sentimental nurse who cares for Grant. He privately nicknames her The Amazon due to her height. She is easily winded by physical exertion and tends to offer unprompted consolation to her patients, which irritates Grant.

The Matron is the composed director of nursing at Grant's hospital. She possesses unshakable poise and is thoughtful in her assessments. When viewing the historical portrait, she offers a uniquely empathetic interpretation that strikes a chord with Grant.

The Surgeon is Grant's attending doctor who assesses his physical recovery. He views the world strictly through a medical lens, noting that the king in the portrait looks like a polio victim, and admits he might have enjoyed history more if it included visual aids.

Edward IV is the charismatic older brother of Richard the Third. His secret pre-contract of marriage and subsequent death set off the succession crisis that drives the historical mystery Grant investigates.

Elizabeth Woodville is the widow of Edward IV and mother to the Tower Princes. Grant finds her historical actions contradictory, as she seemingly remained on good terms with Richard during his reign but was stripped of her wealth and sent to a convent by Henry.

The Tower Princes are the two young sons of Edward IV and Elizabeth Woodville. Their disappearance and presumed murder form the core of the cold case that Alan Grant investigates from his hospital bed.

John Morton is a bitter foe of Richard the Third and a conspirator against his reign. Grant and Brent discover that Morton authored the heavily biased historical accounts that later historians accepted as objective truth.

Thomas More is a famous historical figure whose written account of Richard the Third is highly respected by the general public. Grant and Brent discover that More was a child during Richard's reign, meaning his widely accepted history is based entirely on hearsay rather than firsthand observation.

Tyrrel is the courtier historically accused of carrying out the murders of the Tower Princes. Grant scrutinizes the historical accounts of his alleged confession and his actions during the period following the princes' disappearance.