Exit the elevator and you will find yourself in a room containing a save station (ss24), a shop and a bench. Hold off on using them for a second though because you will be attacked by a leaper and a legless spitter. Once those two annoyances have been terminated go do what you need to do in terms of upgrading shopping and saving. I would recommend purchasing the detonator if you haven't already (and a tonne of ammo for it if you are on your second playthrough), there is a missable achievement /trophy 'Elevator Action'coming up in a short period of time that is much easier to earn with it.
Continue down the ramp and through the door. Follow the walkway here down, passed the locked elevator and into the door to the left. Continue through thesmall room to exit onto a balcony in zero gravity mode.
Shoot the red thrusters on the piece of debris blocking the entrance to the room to move it out of the way. There are another two pieces of floating debris above the elevator, shoot the thrusters on both of these to clear the shaft. Fly all the way to the ground floor beneath the elevator and land. Look around near the bodies here for a Schematic (Schematic 12 - Ripper Blades). Fly down the elevator shaft and pick up the power node (19) hidden here. Look at the bottom of the elevator and shoot both thrusters to send it up to the locked door above.
Return to the balcony and re-enter the gravity zone. Ignore the now functional elevator for now and kill the leaper that comes down the ramp to greet you. I recommend that you return to the previous room and save your game before you enter the elevator so you can retry the next section if you miss the achievement/trophy.
Enter the elevator. As the elevator rises up from the station to the solar array, you will be attacked by a large number of tripods who will jump on the windows and attack you. It is not necessary to kill them all as they will drop off automatically eventually, but you will get a trophy/achievement 'Elevator Action' if you are able to kill them all. Equip the detonator, a single shot from this has the power to knock a tripod off the elevator and kill it, just repeat a few more times and the achievement/trophy 'Elevator Action' is allyours!
Get off the elevator and turn left, follow the walkway around and you will see a pair of cysts in front of some yellow lockers. Destroy the cysts then open the lockers, one will contain a schematic (Schematic 13 - Force Gun). Follow the catwalk around and climb the ramp to the door - be sure to destroy the cyst above the door first though!
Once indoors a hologram appears in front of you. Turn to the right and look in the room here for a text log (Log 22 - Personal Log: Howard Phillips). Pick up the body on the bed and take it past the hologram to the locked door. After a quick scan of the body, the door will unlock. Leave the body here. Before you enter the next area, you can grab a power node (20) off the drink machine and use the shop in the room to the left (be careful of the cyst nearby) and save your game at the save station (ss25).
When you are ready, proceed through the security door. Continue along the path provided until you reach the hologram. The hologram will then detect that you are not supposed to be here and activate the security defences. Pick up one of the metal cylinders on the floor nearby, turn around towards the direction you came from and use kinesis to toss it through the lasers, detonating the mines here. Continue right into the side corridor, using the same object as you go to get rid of the laser mines. Between the two sets of mines in the side corridor,examine the box on the wall for a power node (21). Once you reach the far end of the room, open the door, eliminate the crawling slasher and enter the large room.
In the far left corner, you will see a weak piece of glass we can use to create a vacuum. As before, breaking the glass will create a vacuum and unfortunately it is between a pair of mines, wait for an enemy to appear and destroy one of the mines and then focus on shooting the red triangle before you get sucked outside and then mop up any survivors. It is very likely you will need to defeat a leaper and a small number of crawlers following the window closure.
Once the room is clear, go over to the hologram and enter the room to the right. Look in the lockers here for a text log (Log 23 - Personal Log Howard Phillips 2). Then turn around and hack the panel here to activate the elevator in the previous room. Return to the previous area and kill the two additional slashers and the leaper who attack. Get on the elevator and take it up to the second level.
Exit the elevator and head over to the bench in front of you. Turn around to face the elevator and wait a couple of seconds as a slasher will follow you up. Kill it, then either upgrade your stuff, or continue along the balcony to the right. Use kinesis to move the hanging object out of the way and then use kinesis again to lower the bridge opposite the gap. Continue across. Shoot the laser mines that appear at the end of the bridge, then head around the corner to the left to find more. Pick up a nearby object and toss it through the laser to detonate the mines, and then explore the lockers here. One contains a power node (22). Exit the side area here and kill the slasher that jumps out of the vent. Continue to the save station (ss26). When ready, open the door to the left.
This room is essentially the same as the previous circular room in which the AI first used the laser mines against us. This time the oxygen and power will go out, and to add to the fun there is a stalker and a legless spitter inhabiting the immediate area. Once you have destroyed both of these, hack the panel at the far end of the room to open the door. You will now enter the mainframe area.
Take the first left and pull the kinesis panel off of the wall. Enter the vent here and exit into the right hand mainframe room. Remove the three kinesis panels from the walls here, being careful to kill the swarmers when they come out of the far right panel. You will notice that behind the three panels there are two areas with red lights above them. We need to pull the fuses out of both these sections and insert them into the empty slots on the far right section of the room. Each fuse has a different pattern on it. If you look on the floor in front of the window, you will see which fuse goes where. Place each fuse in the slot required and if it is in the right place it will turn green. Easy! Just do that four times then hit the panel that appears and then return through the vent to the previous area.
Now hit the blue panel to the right of the vent entrance and then crawl into the left hand mainframe room. Walk towards the window and a super-slasher will emerge from a vent behind you. Deal with that first, and then pull off all of the kinesis panels on the wall again.
Before we look at the pattern underneath the window this time, we can find a secret area if we use the fuses in a certain order. Instead of moving the fuses into such a position on the far left wall so that they are green, they can fit into a second slot in which they turn blue. Place all four fuses on the wall here in blue mode and a panel will reveal itself next to the vent. Use this to rotate the vent to a secret room.
Note: Crawl through the vent and grab a pair of power nodes (22 & 23), some cash, a ruby semiconductor and the Peng Treasure for the achievement/trophy 'Collect Peng'. Return through the vent to the previous room.
Now arrange the fuses on the wall according to the pattern in front of the window so they all turn green. Again activate the switch that appears, and then return to the previous area. As you exit the vent, a super-slayer will come to attack you from your right and a slasher will come from the left. Use stasis if needed and eliminate the pair of them. This will cause a platform to rise up directly in front of the vent. Around this platform, 5 purple mainframe circuits will appear. We need to destroy these. Blasting two of these will cause a slasher to appear, and again after blasting four a second slasher will appear. Once all five circuits are down for the count, continue round the room to the left.
Note: For destroying the mainframe, you will earn the achievement/trophy 'Shut Down'.
Continue through the door here and along the corridor there are several cysts here and a number of necrospiders which act like swarmers and will try to jump on Isaac and strangle him if they get the chance. If this does happen, mash the control button displayed on the screen to fight it off. Once clear, enter the next room.
You will find yourself up on a balcony overlooking the floor below. Move forward and you will see a super-slasher climb up over the railing in front of you. Kill it then turn around because you are likely to have a leaper join the party. Once these two are dead, look out for three lurkers who are liable to start firing projectiles at you. Continue along the balcony to the end and use a power node to open the door to the left of the save station (ss27). This will cause a leaper to appear and attack you. Defeat it before heading into the newly unlocked room. Inside you will find a text log (Log 24 - Personal Log:Howard Phillips 3) and a schematic (Schematic 14 - Contact Beam). Return to the balcony area and use your suit locator to mosey on over to the hackable blue panel. Hack it to open the door here.
Continue along the corridor here into a control room. Activate the blue monitor here to raise the platform. Exit the room to find yourself in space. Here, in space we will also meet a new necromorph form - the nest. These Large growths appear a few times throughout the game and have three large red bulbous tentacles that fire explosive, insect-like projectiles at you. Shooting all three of these tentacles will eliminate the nests. Defeating these necromorphs will usually yield a ruby semiconductor.
Once you have dealt with the nest, have a look around and you will see that one set of solar mirrors is lined up, so we need to re-align the remaining two pairs of solar mirrors to match this. This is quite easy, simply fly to both of the lower mirrors and use the small control panel to the left of the mirror itself to direct the direction of the light shining on the mirror to its opposite. Use the oxygen refuelling panels scattered around the area if you start to run out of oxygen, but it really shouldn't take that long. When the mirrors are aligned, use the suit locator to return to the control room.
Activate the ejector seat here and prepare to dodge debris as you fly towards the station. You will want to fly to the right, then to the left, and then backt o the right about halfway up the screen, then back to the left again and through the pipe. Next you need to align Isaac with the green square on the large block so that he flies through it. Move to the right again and then line yourself up with the yellow square onto the roof top ahead to land safely.
Note: For re-aligning the solar panels you will get the achievement/trophy 'Powered Up'.
Once you regain control of Isaac, move out of the room into the hallway, to the left is a save station (ss28) and to the right is a shop. We have a pretty tough fight coming up so deck yourself with a detonator and whatever other weapons you fancy. Do what you need to do and when you wish to continue, head past the save station and down the ramp exit the door here and you will find yourself back in the transport hub.
Quickly run over to the door that has the sign 'C.E.C' above it and prepare for a fight. Use the detonator to plant mines all around your current position. Next, as the fighting starts from the CEC door look back out into the room and you will be able to see most of the baddies and kill them from long range before they get too close and if they do get too close, our mines will be able to handle them. First up will be a steady stream of 5-6 pack children, followedby a leaper and a couple of slashers. Then, at this point the game seems to break into a free for all - slashers, spitters, leapers and pack kids, just eliminate what you can when you can, use stasis frequently if things get too hectic and keep your health up if it starts to go down. After a short while,the door behind you will open, so back through and it will shut behind you.
You will now be on a cargo lift, activate it and ride it on up to chapter 8.
