As a Marine Sergeant, Jack Brady served in China and later on the Western Front, earning a Bronze Star and other commendations, he's believed to have worked as a mercenary after the war, and to speak Turkish, Arabic and several Chinese dialects. Had a long police record for brawling and assaults.
Brady killed an opponent in a fight in California, and was arrested for murder. This piqued the interest of Roger Carlyle, who had just been expelled from USC. The two formed a close alliance, amazing everyone who knew Roger, who had never formed any strong friendship before. After Brady was acquitted, purely by the efforts of Roger's legal team, the two men became virtually inseparable, and so it was inevitable that Brady would accompany the Carlyle Expedition as loyal friend and bodyguard to Roger.
Brady extracted Roger from the Carlyle expedition while they were in Nairobi, and later left the now insane playboy at the Yeung Wo Nursing Home in Hong Kong, before heading to Shanghai, occasionally returning to fund Roger's stay.
It was in Shanghai that the investigators found him, and rescued his girlfriend Choi Mei Ling from the clutches of Ho Fong. Brady told them his story, and accompanied them to Gray Dragon Island, where he helped defeat Sir Aubrey Penhew.
When the investigators returned to Shanghai they found that Miss Choi was dead as a result of the actions of Lin Tang Yu. This sent Brady over the edge of madness. So when he began claiming that Karen Hayes was a reincarnation of Penhew, the investigators felt they had no choice, and deposited him at the Yeung Wo Nursing home with Carlyle, under the name of Charles Keaton, before heading on to Australia.
When Roger Carlyle died at the Nursing Home in January 1926, Brady, still resident there, was convinced he was murdered.
In February 1926, Chuck was informed, by Joe Di Stephano, that Brady had escaped from the Yeung Wo, injuring some orderlies in the process. His current whereabouts are unknown.