The mirror-universe counterpart of Malcolm Reed, a ruthless MACO major on the ISS Enterprise and co-inventor, with Doctor Phlox, of the agony booth.
In In a Mirror Darkly, Major Reed heads security on the ISS Enterprise and takes obvious pride in the agony booth, a punishment device he devised with Phlox that keeps a victim's pain from fading. He backs Archer's mutiny at first, changes sides when Forrest returns, and afterwards eagerly tortures Tucker over the sabotaged cloak.
Aboard the captured USS Defiant he leads the hunt for Slar, the Gorn slave master hiding in the ship's lower decks.
The search goes badly: Reed walks into an explosive trap the Gorn has left and is gravely injured, spending the rest of the story in sickbay while Archer finishes the job himself.