Abiad was a member of the UNSC Navy and a crew member on the UNSC Pillar of Autumn. He was part of the command crew on the bridge and was present for the Battle of Installation 04 in September 2552.
During the boarding of the Autumn, Abiad escaped on Kilo Tango Victor 17  with the rest of the command crew: William Michael Lovell, Aki Hikowa, Singh, Wang, and Ellen Dowski, as well as their Commanding Officer, Captain Jacob Keyes. Also accompanying them were a handful of marines led by Corporal Wilkins.
The group was pursued by The Covenant, whom they managed to evade for a long period of time. Ellen Dowski quickly grew tired of this and suggested that the group should surrender. Certain members of the party became fed up with her rants and tied her up, leaving her for the Covenant. The Covenant eventually found and captured Dowski, who informed them of the group's location.
After Dowski told the Covenant where the group was going, the Covenant were able to quickly surround the group and force them to surrender. This led to the execution of everyone in the group, including Dowski, save for Keyes. Abiad was shot in the face by an Sangheili Minor carrying a Plasma Pistol.