Little Sister Encounter
Big Daddy: Elite Bouncer
Enter the Hephaestus Core area and head through the door to begin the trip around the circular area. You may immediately notice a pair of Splicers fighting an Elite Bouncer in the distance. Hit the Splicers and Big Daddy with the Enrage Plasmid to make sure they ignore you and wait a moment to see where the battle heads. Make your way to the opposite end of the walkway from them. Whether that means you simply stay put near the door, or trade places with them, will depend on what they do.
Wait for the Elite Bouncer to kill off the two Splicers, then lay a series of Proximity Mines down between you and the target. Fire a Heat-Seeking RPG at it to get its attention then back away as it rampages into the Proximity Mines. Finish off the Elite Bouncer with Exploding Buck.
Descend the stairs near the Vita-Chamber and follow the signs towards Heat Loss Monitoring—they’ll direct you to continue in a clockwise direction towards the Gene Bank to the next staircase. Don’t descend the next set of stairs just yet though. First, head to the end of the walkway and locate the safe in the corner behind the machinery.
Safe
Contents: 58 Dollars, 30 Antipersonnel Auto Rounds, 5 Steel-Tip Bolts
This is a tricky safe to spot, as it’s tucked away behind the machinery and rocks at the end of the walkway. Crouch down and crawl behind the machinery towards the Proximity Mine on the ground to access it. It’s a very difficult safe to hack, however, so consider using an Automatic Hack Tool or simply use the Buyout option. That shouldn’t be hard considering all the money you’ve collected from the two Big Daddy corpses you’ve encountered recently.
Descend the stairs to the third level from the top and proceed to the Circus of Values machine (don’t use it!) near the Heat Loss Monitoring entrance. Follow the narrow walkway jutting out into the center of the core to find an Automatic Hack Tool near the corpse.