Linnaeus Pendergast — Pendergast’s father, who was killed in a fire.
Isabella Pendergast — Pendergast’s mother, also killed in a fire.
Boethius Pendergast — Pendergast’s great-grandfather. Lived at the Penumbra, was good friend to famed naturalist painter, John James Audubon.
Helen Pendergast — Pendergast’s thought-to-be deceased wife (maiden name Helen Esterhazy). Helen was a doctor with Doctors With Wings, a group similar to Doctors Without Borders, that travels to third-world countries and disaster areas to help people who would have otherwise had little chance of survival. She was also a skilled big game hunter, and it was one of the pastimes that brought her and Pendergast together. Thought to have been killed in an African safari.
Judson Esterhazy — Pendergast’s brother-in-law. Like his sister Helen, he was a doctor with Doctors With Wings and is a skilled hunter.
Percy Harrison Fawcett — Pendergast’s great-great uncle on his mother’s side. He was an explorer and disappeared in the jungles along the Upper Xingu River (hence Pendergast’s middle name) in 1925 while looking for the mysterious Lost City of Z.
Tristram — Pendergast’s child with Helen.
Alban — A genetically engineered, identical twin to Tristram. Unknown if deceased or alive.