Nikolai was compromised by the Ultranationalist, and was captured and tortured by them. Gaz and the team then worked with the Loyalist to retrieve Nikolai, an informant who gave them the info on the cargo ship. When attempting to leave, MiG's shot at the ship, making the team have to run their way to the Big Bird before the ship sunk into the sea. Despite encountering fighters from the top deck and inside the ship, they dispatch them and find the package, which was a nuclear device. Gaz was part of the SAS team which was Price, Soap, Wallcroft and Griffen, who boarded on the cargo ship to retriteve the package at the Bering Strait. Afterward, Gaz sends him to Captain Price, who puts him through the training course to prepare for their mission at the Bering Strait. He also teaches Soap that switching to his sidearm is faster than reloading his main weapon, and how to use a knife on a watermelon.

On Day 0, Gaz puts John 'Soap' MacTavish through training in Credenhill, England by teaching him how to shoot from cover, from the sights and from the hip.

Gaz joined the Special Air Services and became the second of Captain John Price, and holds the record of the completing the course in nineteen seconds. Gaz was born before the events of the series, and has an unnamed family back home.