
The Legion is soon double-crossed by Major Dupree who is now in allegiance with Ian Dressari. On Kentares IV, the Legion runs disruption missions, taking out key assets to Duke Ian Dressari's forces.

The major offers a contract for the Legion to assist in the retake of Kentares IV on behalf of House Steiner and gives free 'Mechs to the Legion as a gesture of goodwill. Initially taking on mundane escort contracts from the Corvatti Corporation, the Legion is approached by Lyran Alliance mercenary liaison officer, Major Clarrisa Dupree. Eric joins the Black Knight Legion, a mercenary group led by Colonel Lawhorn. The story follows Eric McClair, a recently discharged 'Mech pilot from House Davion. This expansion requires the MechWarrior 4: Vengeance to be installed and is not a stand-alone adventure.

MechWarrior 4: Black Knight is an expansion pack to MechWarrior 4: Vengeance that contains new 'Mechs, multiplayer modes and a black market for trading equipment.
