"The Adventures of Jimmie Dale" – Jimmie Dale is a wealthy playboy by day, but at night he puts on a costume and becomes The Gray Seal, who enters businesses or homes and cracks safes, always leaving a diamond shaped, gray paper "seal" behind to mark his conquest, but never taking anything and just doing it for "the sheer deviltry of it". But he gets caught by a mysterious woman he calls The Tocsin, and she blackmails him to help her in the war with certain crime organizations. "The Further Adventures of Jimmie Dale" – Jimmie Dale wanted to settle with the love of his life, but when she disappears, he is pulled back into the New York's underworld of crooks and crime. "Jimmie Dale and the Phantom Clue" – Jimmie Dale is back in the underworld of New York, and he is destined to find the criminal known as the Phantom, in order to save the woman he loves. "Jimmie Dale and Blue Envelope Murder" – Jimmie Dale tries to protect his friend who received a threat in the form of a mysterious blue envelope, but when the friend is found dead, Jimmie is accused of the murder. To clear himself, Jimmie must resolve the envelope's mystery and find out who stands behind the murder, and he must do it while avoiding the police and his old enemies from the underworld. Frank Lucius Packard (1877-1942) was a Canadian novelist best known for his Jimmie Dale mystery series. The character Jimmie Dale is a wealthy playboy by day and a fearless crime fighter by night. Jimmie Dale novels brought the idea of a costume and mask for hero's secret identity, and also established the concept of a hero's secret hideout or lair.