Captain of the Terran Empire's I.S.S. Enterprise NX-01, in the Mirror Universe.

Forrest clashed with the Mirror Universe's Jonathan Archer over who should command the ship. Ultimately, Archer's mutiny put Forrest in the brig, only to be freed by the Mirror T'Pol.

During Enterprise's attempt to steal the future starship Defiant from Tholian hands, I.S.S. Enterprise was destroyed, with Forrest on the bridge.