10 Minutes Too Early Achievement in Halo: The Master Chief Collection

Holo-Drones are small Covenant devices that provide holographic duplicate decoys of important personnel. Physically, they resemble inactive Plasma grenades in size and shape. On the aforementioned mission then, the Heretic Leader uses two Holo-Drones in the final fight against the Arbiter. Earlier in this mission however, you can find a single Holo-Drone.

As soon as the mission begins, walk through the initial room and past the corridor where Flood are fighting beneath the glass floor. In the next room, stick to the right walkway and jump on the closest pillar, then on the pillar closest to the glass tube. From here, destroy the tube with your weapon and then crouch jump onto the center structure. Once here, turn around and crouch jump onto the ledge above your current position. From up here, you will see two holes in the corner of the wall. Get as close to the right hole as possible and perform a grenade jump. Once inside this cubbyhole, you will find the Holo-Drone floating in the air and the achievement will unlock.