William Walcott

Professor Strangerson

Edmund Elton

Robert Darzac

George Cowl

Frédéric Larsan

Ethel Grey Terry

Mathilde Strangerson

Lorin Baker

Joseph Rouletabille

Jean Del Val

Jean Sainclair

W. H. Burton

Daddy Jacques

Henry S. Koser

Mr. Bernier

Jean Ewing

Mrs. Bernier

William Morrison

Judge Marquet

Louis R. Grisel

Mr. Maleine

John McQuire

Mr. Mathieu

Catherine Ashley

Mrs. Mathieu

Ivan Dobble

The Green Man

Émile Chautard