The eldest child of a family of four in Pittsburgh, Christopher [Millard] endured chemotherapy to treat his rhabdomyosarcoma, a cancerous tumor inside the nasal passages. After a summer of illness and hospitalization, he returned to school and was asked to write about what he did on his vacation. Unable to put that experience on paper, Christopher asked for another assignment. His teacher told him to choose any experience he wished. A fan of the tales of King Arthur and his Knights of the Round Table, Christopher composed a story about an unknown member of the court, Sir Millard. Just a squire when the story begins, Millard sets out to battle the evil sorceress Raptenahad and win the Diamonus Quadrus - the Four Diamonds of Courage, Wisdom, Honesty and Strength - so he can become a true knight. Consciously or unconsciously, Christopher transferred his battle against his cancer, and how it affected his family, into this allegorical tale of a knight's quest.

The film "The Four Diamonds" moves back and forth between a fictionalized version of Christopher's fight with cancer and his sword-and-sorcery fantasy, with several of the actors playing dual roles. The film stars Thomas Guiry ("Lassie") as Christopher and Sir Millard; Christine Lahti as Christopher's oncologist, Dr. Burke, and the sorceress Raptenahad; Kevin Dunn as Christopher's father, Charles, and the wizard Charles the Mysterious; and Jayne Brook as mother Irma Millard and the wise Hermit. Sarah Rose Karr plays Christopher's little sister, Stacie (represented in the story by the elusive Stacia Swan); Michael Bacall plays fellow cancer patient and friend Tony Falco. Peter Werner directs from a script by Todd Robinson; executive producers are Joe Byrne and Jeb Rosebrook.