“Boarding Action” is a new mission in Halo: Campaign Evolved, set about a year before the original game, in which Master Chief and Sergeant Avery Johnson explore a Covenant mothership. The guide explains where to find its three gameplay-modifying skulls and one lore terminal.

– Malfunction skull: after defeating white-armoured Hunters, take the right-hand route, drop by the Seraph, and find it on the walkway behind a turret.
– Johnny Ammo Seed skull: in the white-and-gold area, clear enemies, use the upper route through the left doorway, then find it on the curved central walkway.
– Leadhead skull: after Johnson activates a gravity lift, enter the newly opened doorway behind and left of it; the skull is at the corridor’s end.
– The Path terminal: immediately after taking the gravity lift, turn around and enter the right-hand door at the back.