Serpent Society. He is attacked and poisoned by Viper, and mistakenly fights Battle Star. Dunphy is arrested by the CSA and held for questioning about The Captain's activities. When Dennis is finally released by the CSA, he seeks out the Captain, discovering that not only had his team disbanded, but that the East Coast Avengers team had also just disbanded and that the Captain is seeking new members. The Captain asks Demolition Man to join the Avengers and they immediately leave on a mission at the request of Battlestar. Battlestar's partner is John Walker, Captain America's replacement, who was captured by Flag-Smasher and his group ULTIMATUM. While Battlestar and the Captain investigated ULTIMATUM's Arctic base, Demolition Man is left with their plane. During the fight, the Captain discovers that Flag-Smasher's base contains a doomsday weapon (an electromagnetic pulse generator), and he orders Dunphy to set the plane on course to crash into the base and then bail out. Dennis sets the course, but then sees an enemy agent land on the plane. Dunphy elects to stay on the plane to ensure that it crashes. The plane explodes, apparently with Dunphy in it, and Captain America is unable to find any trace of him. In a later adventure with Jack Frost, Captain America sees what he believes to be Dunphy's body frozen in suspended animation in ice near the North Magnetic Pole in the Arctic. However, he is unable to free him. Demolition Man survived the explosion, but suffered wounds that rendered him mute and in a stupor, and is discovered living among the Inuit. During a backup story to "Operation: Galactic Storm", he is rescued by U.S. Agent and the Falcon and recovers under Avengers' care. In time he becomes a hero of a subterranean group of homeless people called the Zero People. Dennis assists the Avengers who are under attack by Morgan LeFay's forces. It was later established that Dunphy had become delusional and mentally unstable. His intentions remain pure, but he had begun to believe that a "Cosmic Gamemaster" had asked him to retrieve the seven Infinity Gems, which D-Man carried out by stealing common jewelry. At Ben Urich's request, D-Man's hero Daredevil descends into the sewers and persuades Dennis to get some help. In Civil War: War Crimes, an unnamed newspaper carries the headline "D-Parted: D-Man On The Run After Whereabouts Revealed By Anonymous Tip". Dennis was