Hastati Squad, the newest batch of freshman cadets at the UNSC's Corbulo Academy of Military Science, pays the price for cadet Thomas Lasky's tactics.

Cadet Michael "Sully" Sullivan continues to decode the hidden ONI combat video as Lasky's struggle with his place in the UNSC ignites with fellow cadet Walter Vickers. After a classroom confrontation with Captain Mehaffey and a challenge from Chyler, Lasky pulls Hastati Squad back from the brink...at a terrible physical cost to himself.

While Corbulo Academy is being destroyed by the Covenant invasion, the surviving cadets fight bravely alongside their only hope: The Master Chief.

After a terrifying night of combat and loss, Lasky makes a life-or-death decision to help the Master Chief... but will it be enough to save them all from the Covenant?