Locations of Skulls and Terminals in Halo Campaign Evolved's 'Pillar of Autumn' Mission

The 'Pillar of Autumn' mission in Halo: Campaign Evolved contains four hidden collectibles: skulls that modify gameplay and terminals that expand the game's lore. Despite the level's linear design, these items are placed in frustratingly tricky spots. The author admits to missing all of them during their first playthrough.