Let's Play Doom 3: BFG - Part 43 - Phobos Labs Molecular Research

Watch here for better quality: https://youtu.be/2yAcXz_RgfY We visit McNeil in her office. She discovered that the Hell Heart is, in fact, the Heart of Hell (Duh!) - a weapon made by the demons themselves to aid them in their war against the Martian race. She also reveals that the Hell Heart also works as portal device, so the only way to stop the invasion is to return it to Hell, and the only to way to gain access to Hell is to use the old main gateway at Delta Labs, which is sealed since the Mars outbreak two years ago. McNeil then orders the us to shut down all four core systems of Mars to power up the old teleporter on Phobos Labs, which is the only way to reach the sealed Delta Complex. As we go to many sections of the base, we encounter the third and final Hell Hunter, the Invincibility Hunter. The Invincibility Hunter is of course invincible as long as he's able to draw electricity from the power cores in the room after weakening him. All four cores must be exposed and destroyed before the Hunter can be killed. Once he's dead, the Hell Heart is fully powered and we gain temporary invincibility while it's activated. Doom Marine R is now a force to be reckoned with.