At the end of the Pelagic 2 level after completing most of your objectives and finding Elvis, you're supposed to go through a massive corridor filled with guards hiding behind crates and such. Doing so is a massive struggle, especially on harder difficulty settings.Thankfully, you have the X-Ray Scanner and can use it to bypass the entire process. Remember the large room on the top floor where you have to activate the Moon Pool Lift? Rather than going through the entire level and opening the door in the manner you're supposed to, slap on the X-Ray Scanner and activate the computer from through the wall.If you've met up with Elvis at this point, the mission is over. If not, you need to run downstairs and fight your way through the guards until you reach Elvis. From there, return to your shortcut and to the Moon Pool Lift to end the level.Regardless, you get to bypass the hallways of death at the end of the level, which is what this glitch is used for in the first place.