On Great Journey, it is possible to sneak inside the Scarab. Simply put, you sword fly into it. Here's how. Near the end of the level (right before the Banshees), have a Carbine and Energy Sword. As the door opens to reveal the Scarab, use a Brute to sword fly into the Scarab. Seconds after entering the Scarab, Johnson will follow, equipped with a Plasma Pistol.