First one on right, two on left, two more on right, then on the left. Kendra tells Isaac to return to the Medical Deck and create a poison that she mentally fabricated of in order to kill the toxic Necromorphs and Hammond says he is going to Hydroponics to try and slow the Necromorphs down long enough for Isaac to create the poison.
Continue to shoot the inside of his mouth until it clamps shut and more tentacles appear—focus on them until his mouth opens once again. Dead Space 3 secrets in chapter 4: History' Ember.. EarthGov Artifacts (2) S.C.A.F. Now interact with the main terminal and collect the sample it leaves. Now follow the walkway to the other side, but get ready for an alien to pop out of the ventilation cover as you descend the ramp—try using Stasis, since there's a recharge kit nearby, by the main terminal. Oh, and stand back in the far-left corner, as four aliens are about to board your ride; since the last two appear together, you may want to Stasis them.
In the Mining Bay, get ready for the three usual suspects to appear. Along the way, prepare to tackle a couple of aliens that pop out of some manholes in the Tram Tunnel, then continue through the Cargo Hallway. With the Generator ready to go, jump to a walkway above and activate the terminal to activate the centrifuge. For you see, while you may be the only living human left on the ship, you're not exactly alone…. On level 03, the vanishing man appears and whispers 'make us whole again' and when Isaac approaches him, he runs off. Be careful as you exit the room back into the anti-gravity chamber, as two aliens are about to come flying your way. Look for an item in the waiting area, then enter the Tram Station Hall door. Now cross the walkway to find the Maintenance Bay Key, a Text Log, and another item. Stasis's effectiveness, when used offensively, can not be overstated. And because time is short, it's crucial you begin your trek as soon as you grab the DNA, and don't wait for the radio conversation to end first. Afterward, collect the goodies scattered about, including a Gold Semiconductor in the corner. Once Wall Guy's down, ride the nearby lift up a level, then prepare for a head crab just across the gap.
Now simply ride the lift back down, then take the main elevator from the dusty room to the Processing Level (but watch out for an enemy to drop down during the lift). Inside the Tram Tunnel, look for an item along the left barricade, then continue to the malfunctioning door. Head back upstairs to the Atrium and approach the door in the back…slowly.
Also, look out for an item in a locker, and another near the door you entered from. Isaac makes it to the bridge, where he runs into his largest enemy yet: a Brute. With the array fixed, head back to the Comm Room via the same way you entered, then interact with the control panel overlooking the satellites. Go through the door leading to Control Room Barracks and look for a Save Point on the left, as well as a Bench and Store. Off the tram, grab a couple of items and check out the bench if you wish.
Now here's the thing: As soon as you destroy three of his antennas, he'll grab you and hoist you into the air. Turn right and proceed into the Residential Lobby. Use your most powerful weapon and shoot them as quickly as you can.
Continue through the door at the end of the hall. Head past the first door for now to gather all the goodies from the cupboards and a Gold Conductor in the corner (in addition to a Stasis Recharge Station on the right). You may find that several of them are out of reach, so simply zero-g jump to their location and grab them from there. Simply score the ball in any of the four "hoops" to score a point. Our Dead Space 2 Walkthrough provides a full walkthrough, tips for defeating bosses, and hints for obtaining powerful gear. Afterward, launch yourself to the wall just below said opening, then walk on through it to the door leading into the Air Filtration Room. Tackle the aliens from the entrance, before igniting the engine. After riding the lift, check the lockers for some items, then go left and interact with the panel to cause the Marker to appear. Once off the elevator, proceed into the Residential Hall, but get ready for several aliens to invade from a vent on the right. Ah yes, the Cryogenic Lab. Dead Space's aliens like to hide and pop out at the most inopportune times, whether it be from a vent or around a corner.