The Mission to Antares IV took place on an old power station located in a dormant volcano.
The station was captured by the Orion pirates, the local security force sent a team to investigate, when they haven't heard from the team in a while, the Earthforce sent Sydney Stockman and the Delta Squad.
The team arrived on the Hawk, but after waiting for sometime for Syd to arrive, they decided to act on their own. Entering the facility, they passed a number of dead bodies, presumably the original security team that did not return, and some large footprints that were probably from some beast that killed the team. Tapping into the security system, they discovered that the pirates placed several bombs in hopes to reactivate the volcano, destroying the settlement near the volcano.
The team encountered several members of many assault teams, eliminating them as they went. Various parts of the facility were damaged, which gave the team cover. After encountering auto turrets, energy nets and several assassin droids, they completed their mission.