Halo Alpha
Halo Alpha

The Callisto Incident was an event which effectively sparked the Insurrection; an undeclared war between the United Nations Space Command and the Insurrectionists. The incident gets its name from UNSC Callisto, a UNSC corvette.[1]


In the early 2490s the colony of Levosia was suspected of diverting refined selenium and technetium, elements used in the production of Shaw-Fujikawa Translight Engines, to the black market. UNSC CENTCOM, desperate not to allow insurgent forces access to slipspace drives, ordered the Navy to blockade and search all ships in the 26 Draconis system for contraband.

The Callisto stopped and boarded a trading vessel. The merchant crew was skittish due to rumors of impressment during similar searches in the Outer Colonies. A weapon was drawn and shots exchanged, resulting in the death of three naval officers and twenty-seven merchant crewmen. No contraband was ever discovered. This sparked outrage throughout the system.

Thirty-seven days later the Callisto boarded another merchant vessel. They were courteously allowed aboard; however, they found the cargo bay empty. The bay doors then opened and the boarding party was blasted into space. The merchant crew then swarmed into the Callisto, murdered the remainder of its crew, and gutted and replaced its computer system.

In response the UNSC dispatched a battle group of three light destroyers - the Jericho, Buenos Aires and Las Vegas - to hunt down the renegade ship. The ships' crews and weapons were inexperienced and untested.

On March 2, 2494, the battle group confronted the Callisto in the 26 Draconis system . The destroyers all fired six of their seven Ares missiles, and in response, the Insurrectionists maneuvered behind an asteroid, which it then detonated in the direction of the UNSC vessels using a nuclear warhead planted beforehand. The Buenos Aires was destroyed and the other two destroyers severely damaged. The entire bridge crew was killed or incapacitated, with the exception of Second Lieutenant Preston Cole, who was left unharmed. As the last remaining bridge officer, Cole took control of the Las Vegas.

Cole signaled the Callisto, declaring their surrender. However, he ordered the crewmen to remove the ship's last Ares missile from its silo and transport it to Cargo Bay 5. When the Callisto docked with the Las Vegas at Cargo Bay 5 the missile was fired directly into the corvette, crippling it and forcing its surrender.


Cole's faked distress signal was both a stroke of genius and breach of protocol so severe that UNSC CENTCOM dithered over whether to award him the Legion of Honor or have him court-martialed. Ultimately they did neither, to avoid setting precedent. However, from that point on, Cole could never again send a distress signal in enemy territory; no one would believe it. As he stated in his personal log: "Surrender, quite literally, is no longer an option for me."[2] The incident itself is considered to have been one of, if not the, critical catalyst for the Insurrection.


  1. Halo: Evolutions - Essential Tales of the Halo Universe, page 436
  2. Halo: Evolutions - Essential Tales of the Halo Universe, page 446