Derek "Frost" Westbrook

Sergeant Derek "Frost" Westbrook is a Delta Force operator assigned to Team Metal, operating under the command of Sandman. Frost is one of the playable characters and one of the main protagonists in Call of Duty: Modern Warfare 3.

Operation Kingfish
Frost participated in Operation Kingfish alongside Sandman, Gary "Roach" Sanderson, John Price, Soap MacTavish, and Simon "Ghost" Riley. He provided sniper support for Bravo Six before aiding them in trying to find Makarov inside the safehouse. After Makarov was not located, the team was extracted by helicopter, except for Price, who sacrificed his freedom by staying behind, fighting the Russians until he was captured and sent to a gulag.

Delta Force Sergeant
Frost participated in the Battle of New York during the events of "Black Tuesday" and "Hunter Killer". His team, Team Metal, was assigned to destroy a Russian Electronics Jammer on the roof of the Stock Exchange. Facing heavy resistance, Frost and his team manage to disable the Jammer, evacuating aboard a Black Hawk helicopter. They are then pursued by a group of Mi-24 Hind gunships in the skies above New York.

Metal Team is then grouped with a squad of Navy SEALs to take control of a Russian Submarine (acting then as a command vessel). Frost and Sandman sneak aboard the sub and re-program the missiles to launch on the Russian fleet, effectively crippling Russia's seaworthiness and forcing them to retreat as Frost and Sandman make their escape via Zodiac.

Rescuing the Vice President
Their team was later assigned to a hostage situation in Hamburg, Germany involving the Vice President. They get the Vice President and head to Paris, France to capture Makarov's bomb maker Volk under intel by John Price. They received orders from Overlord to rendezvous with and provide backup to the GIGN forces led by Sabre. After meeting up, they carry out their orders of capturing Volk alive.

Assisting the GIGN
On their way to find Volk, they are met with heavy resistance from Russian soldiers and armored vehicles, but thanks to assistance from an AC-130 gunship in the airspace they were able to locate Volk, who was hiding in the catacombs. As Volk manages to run away, Frost, his team and the GIGN fight their way to pursue Volk which gets away in a car. Frost's team managed to get in a van and chase Volk throughout the streets of Paris. They managed to apprehend Volk and received orders to take Volk to the extraction point. However, it was compromised and they had to get to the secondary extraction point, which was near the Eiffel Tower. Receiving air support from the AC-130, they managed to get Volk out of the battlefield.

Finding Alena Vorshevsky
Frost's last mission was to rescue the Russian President's daughter Alena Vorshevsky, who was hiding in Berlin, Germany. After fighting through the city to save her, Alena is still captured by Makarov's men and taken to Siberia.

Trivia

 * If the player looks at his gloves they will see the logo for Oakley Inc.
 * Frost is the sole survivor of Delta Force's Team Metal.
 * Frost is the only member of Team Metal to have his full name revealed.
 * In Multiplayer, there is an emblem of Frost.
 * In the cutscene in "Black Tuesday", in Sandman's dossier, it is incorrectly stated that Frost is a Staff Sergeant, when he is a Sergeant.
 * If you listen to the in-game files of Captain Price you can hear him shout "Westbrook!". This could mean Frost was originally meant to be appear in Down The Rabbit Hole but the developers changed their mind in the last minute.