A Dreadnaught-class heavy cruiser, known as Mercury, was under the control of an unidentified independent group. This vessel once assisted the Alliance by materializing from hyperspace in close proximity to the CR90 corvette Razor, which had been seized by the Avenger. It recovered escape pod V33-1XP that held a solitary Rebel crew member, who possessed the plans for the second Death Star.
Subsequently, Mercury transported the escape pod to the designated meeting location with the Independence and released the pod once more, enabling it to reach the Cruiser. However, the Avenger reappeared, accompanied by the Executor. The crew of the Independence successfully defended the pod as it travelled toward the Cruiser. Mercury, lacking the necessary firepower to defend against either the Avenger or the Executor, departed from the area.
Mercury's appearance functions as a "deus ex machina," as it unexpectedly arrives to assist the Rebels during their most dire moment without any prior explanation. The game scenario does not address the identity or allegiance of the Mercury, nor does it explain the reason for its intervention on behalf of the Rebels.