Resident Evil 3 Sewers - Battery Pack location for locked doors and the Security Office explained
How to fully explore the Gamma-filled area.
The Sewers objective follows on from the brief but intense Lure the creature away chase in Resident Evil 3.
The Sewers introduces a new adversary - the Gamma - as well as a new obstacle in your path - locked doors which require a Battery Pack.
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Exploring the Sewers in Resident Evil 3
Enter the safe room on your left and save your game. Get the Sewers Map file from the wall, as well as the Red Herb from the side and ammo from the locker, then leave the room and continue down the walkway.
Ignore the window into the office on your left - you cannot access it for now - and head down the passage until you come to a fork - a door on your right, and the sewer waters on your left.
Get the Increased Sewer Security File from the wall next to the door to learn you need a battery pack to open these types of locked doors.
How to open locked doors with the Battery Pack in the Sewers
Go left into the water and slide down further into the sewer.
There's an easily missed Grenade on the right wall, and behind you to the right, a yellow ladder. You need a battery pack to explore this area, so remember it for later.
Head down the sewer to come to a fork. Go left. You'll soon run into a giant mutated fish creature - a Gamma.
Despite their size, these are fairly straightforward to deal with. Walk backwards while facing it, and fire into its mouth when it's open. After a few shots it'll close up and possibly stop, but repeat this process - backing away when it's walking at you and firing when it's mouth is open - until it's dead. It's slow and predictable enough you can use a Handgun here - though it might take a full clip of 15 rounds to down.
At the end of the passage is a short ladder to another safe room.
Get the Research Assistant's Logs from the desk to learn more about the Gammas, and another File next to it named Invoice from Gun Shop Kendo.
This explains how Grenade Launcher ammunition works - useful since there is one right in this room. Save your game, and make sure you get the Lockpick if it's in the item box.
Head back out to the fork, and take the other direction. Another Gamma will emerge. Fire using the Grenade Launcher at its mouth, and it'll go down in a single blast - after some prolonged burning, of course.
What follows is another fork.
Go left first to the Lab. Before you climb the short ladder, get the Flame Rounds on the right as you approach, and shoot the Bobble Head through the grate at the end.
Climb up the ladder and into the Lab, where you'll find the Battery Pack we're looking for.
There is also some consumables to get, the A Love Letter? File from the desk, and a locker to use the Lockpick on for some Grenade Launcher ammo crafting.
Leave when ready, and head down the other fork going north to a deadend, with the Sewer Worker's Notes, Shotgun ammo and a Green Herb.
How to access the Security Room using the Battery Pack in the Sewers
Now go back the way you came - there's a Gamma on the way - to the first fork, and head north to where you slid down, where there's a yellow ladder.
A Gamma will block it, so dispatch then head up the ladder and the spiral staircase that follows, and use the Battery Pack on the locked door. It'll be removed from your inventory - which is important to note.
Inside the room, go left round the corner for another Gamma encounter. You're now in an oval-shaped room. Go left and unlock the yellow door, allowing you to return to the door we just opened using the Battery Pack.
Remove it - as since we've just unlocked the yellow door, we don't need it to head back through - and return to the oval-shaped room. There is a door in the north-east you can use the Battery Pack on, leaving to a Security Office where you can find ammo and a Hip Pouch inventory upgrade.
Our full Resident Evil 3 walkthrough explains every aspect's of Jill's, including the Shotgun location, Bolt cutters and Lockpick locations, how to reset the Circuit Breakers to restore power in the Substation, find the Drugstore safe code solution and Aqua Cure clue, Police Station Safe, Locker codes, Hospital safe code and courtyard box for the Magnum explained.
How to leave the Sewers
When you leave, grab the Battery Pack again, and head to the west and kick the ladder down to return to the first locked door we came across in the sewers.
Use the Battery Pack on the door to open it. As you walk up the long stairs, turn around and look behind you to see a Bobble Head on the ledge above. Shoot it.
Continue up the stairs and Jill will call Carlos. Climb the ladder for a cutscene, which leads to an encounter with Nemesis in the Demolition Site.
