We'll show you how to get the power switch back on, navigate your way through region, and take out all the infected enemies as you make your way to the outside once more.
Head into the mall and walk straight ahead until you come to a food court. Take all of the supplies that are littered around this area, then locate the door. It's magnetically locked, so you need to find a way of getting the power switched back on.
Look at the cables on the floor and follow them towards a set of doors. Go through them, grab the ammunition lying around on the floor, then keep heading forwards until you come to more doors. These are blocked, so get into the shallow water and make your way towards the loading area where the trucks are. Look for the generator on the right-hand side of this area, then try to activate it. It needs fuel, so pick up the nearby canister and head towards the trucks.
You'll be ambushed at this point, so get your gun and your knife ready. Once all of the infected are dead, approach the white truck, fill the petrol can, then go back to the generator and fire it up. You need to avoid the water now, so open up the nearby door and go through it.
Climb up the ladder until you reach the air vents. Move over these vents until you get to the platform near the trucks. You'll see a garage door here. Open it and pull the pallet on wheels out of there.
Open the next garage door along and take all of the goodies inside, then move the pallet so that it's just underneath the door. Clamber up the boxes between both doors, then move along the top of the propped-up door until you're on top of a massive air-con unit. Keep moving along the ducts here until you're at the door to the pet shop.
Kill the first infected in the shop with your knife, then shiv the Clicker through the office window. Make sure you take all of the supplies nearby, then go into the pet shop itself and kill any other infected that remain. Create distractions with bricks and bottles to make life a little easier for yourself.
Once you've taken everything from the pet shop, head towards the shutter by the front of the door and slide it open. There are two infected that need to be taken out now. Try to pick them off individually, but avoid using your gun so you don't draw more attention to yourself.
When the coast is clear, return to the magnetically locked door, open it, then go upstairs. Listen to the recording in the tent on your left, then go back outside, travel over the glass, and get in the helicopter.
If you need help tracking down all of the Left Behind collectable items, head back to the first page of this guide.