Dr. Dunn is a 76-year-old, wheelchair-bound scientist who works for T.H.U.N.D.E.R. With the help of the late Dr. Jennings, he has designed android bodies into which a human consciousness can theoretically be transferred. Dunn decides to become the first to try the switch because he is near death. Entering the transfer "cabinet, " he successfully makes the transition, whereafter, simply by willing it, he can shuttle his mind over any distance into one of the other androids at T.H.U.N.D.E.R. headquarters. Each of the androids weighs 350 pounds and possesses extraordinary strength. Equipped with a cloak of invisibility--which when activated by twisting the dial-fastener, "activates a forcefield in which the alignment of the molecules permits light to pass with no reflection" --Dunn is code-named NoMan.
Whenever he is needed, he is contacted via a radio receiver built into the temple of each android. Dunn can only die if he fails to extricate his mind from an android before it is destroyed. Fortunately, each of the T.H.U.N.D.E.R. Agents' bodies--costing $1 Million each--is stronger than that of a human being and can withstand a great feal of punishment. Though he is not human, NoMan can digest food and can fall in love--the latter of which he did with agent Linda Rogers. When not working for T.H.U.N.D.E.R., the former Dr. Dunn conduct research on NoMan's Land, an island in the Atlantic.
NoMan's history is elaborated on in the DC Comics volume of Thunder Agents. By 1969, empathy was no longer an automatic reflex, requiring active concentration to empathy. He came under fire by the T.H.U.N.D.E.R. Agents for almost allowing Kitty to die. In 1973, NoMan's wife hung herself as he watched. The same year, he was dismissed by T.H.U.N.D.E.R. over concerns about his increasing distance. By the present day, he lives with an assistant, performing solitary experiments on his clones. When T.H.U.N.D.E.R. contacts him about helping rescue the kidnapped Raven, he agrees because Raven is his friend. Spider is able to incapacitate him when he comes to Raven's rescue.