The Dead Man was a strip by John Wagner and John Ridgway published in 2000 AD progs 650 to 662. Yassa Povey, a lad living in the war-scarred hellscape of the Cursed Earth, finds a man so hideously scarred from falling in an acid river that his features have been completely eradicated, and he has no memory of who he is. Yassa nicknames him 'the Dead Man', "cos by rights he really shoulda been dead," and the boy and his anonymous companion set out on a quest to retrieve his lost identity. On the way they are haunted by apparitions of a terrifying woman.
It transpires that the Dead Man is, in fact, Judge Dredd, and the woman haunting him is one of the Sisters of Death. The truth of the Dead Man's identity and the fact that Dredd had resigned from the Justice Department and taken the Long Walk were both major surprises to the readers. Although the strip was set in Dredd's universe there had been no indication that it would feature him — other strips set there, like The Helltrekkers, had not — and John Wagner, the doyen of Judge Dredd writers, had (like Dredd himself) used a pseudonym.
The events of the strip were an introduction to the 1990 Mega-City One epic Necropolis, in which Dredd and his colleagues have to fend off an attack on the city from the Sisters of Death and their evil pawns, the Dark Judges. Yassa survived his encounter with the forces of darkness, but was left blinded and suffering from traumatic flashbacks. He was restored to health by the city's medical staff, with the help of Psi-Judge Anderson, after the Dark Judges had been sent packing.