Marathon

The UNSC Marathon was the personal flagship of Fleet Admiral Harper, and the namesake of its class - the Marathon-class Heavy Cruiser. The UNSC Marathon was considered the successor to the Pillar of Autumn as the most famous ship of its line. Fleet Admiral Harper helped to defend Earth from the Covenant with this ship, and it served as the flagship of the Human Navy alongside Cairo Station. The Marathon deployed to protect Cairo Station and was ordered by Hood to take on the Covenant Supercarrier Solemn Penance, the flagship of the Prophet of Regret. Lord Hood promised that he would do what he could against the second carrier and put Cortana in charge of Cairo Station's SuperMAC.

After Cortana wiped the floor with the Covenant fleet, Harper moved in to attack Regret's ship. However, the second carrier moved to defend Regret and was immediately bombarded by Cortana's SuperMAC, which took down its shields. Hood processed a full report to Harper, saying that the carrier was completely disabled and all offensive and defensive systems had overloaded. This was a lie.

When Harper moved in to take down the ship, it fired its topside energy projectors, gutting Harper's ship and killing the vast majority of its crew. Left adrift, the Marathon was able to deploy only three of its original nine hundred Longsword Fighters, which bombed the carrier and blasted a hole in the main power core generator. Harper initially planned to destroy the carrier by ramming the Marathon into the power core, but the impulse engines did not respond. Instead, Johnny flew in and blew the ship up with a Covenant Bomb, escaping in the nick of time and fleeing to the In Amber Clad.

In the meantime, Harper fled the Marathon in an escape pod and hacked the black box of the Marathon to report that all the crew aboard had been killed. He jettisoned an escape pod and activated the ship's slipspace drive via his Admiral Override, teleporting half the ship to oblivion and eradicating all evidence of his escape from the tyrannical Hood...