The mirror-universe counterpart of Travis Mayweather, a MACO sergeant who serves as Archer's bodyguard and finally helps Hoshi Sato take the Empire from him.
In In a Mirror Darkly, Sergeant Mayweather is a soldier rather than a pilot. He sides with Commander Archer during the mutiny against Captain Forrest and is made his personal guard, standing behind him through the raid on the Tholian drydock and the capture of the USS Defiant.
He takes part in the fighting aboard the Defiant and the suppression of the alien crew members' plot.
His loyalty proves to be for sale. At the end of the second part he is revealed to be Hoshi Sato's lover and accomplice, sharing her quarters as Archer dies from the poison she has given him.