Travel west away from the train station and turn left near the Health Station to approach Triton Cinema. Carefully hack the RPG Turret in the distance. Use Electro Bolt on the short-circuiting door to the ticket booth to find a wealth of Proximity Mines and money inside. Gather up the items on the floor and near the bar, then head down the stairs towards the lounge.
Descend the stairs on the right leading to the lounge down below, and watch the two Houdini Splicers dancing in the spotlight. You can take them both out with a single well-placed Solid Slug, but there is always a chance of a glancing blow. If they both happen to survive your attack, simply watch the spotlight to discover the location of the one that is currently posing a threat. The spotlight automatically follows the Houdini Splicer that is about to attack—use this to your advantage.
Safe
Contents: 4 Trap Spears, 4 Rocket Spears, 3 Proximity Mines.
Descend the stairs near the bar in the Triton Cinema lobby to the lounge and hack the Door Control Panel to access the storage room. The safe is located on the wall to the left. Wait a moment or two before hacking the safe, taking out the approaching Splicers first.
Return to the main lobby of the theater and inspect the restrooms to the north of the concession stand to find the Electrical Storm tonic. The first Little Sister you need to deal with is in the main theater area, near the stage. Top off your health and EVE and proceed through the right-hand door to the seating area.
Big Daddy: Elite Bouncer
The Elite Bouncer is essentially a fiercer version of the Bouncer and boasts an increase in armor and health. Its primary means of attack continues to be its Drill. You initially encounter the Elite Bouncer near the stage, trying to protect its Little Sister from a nearby Spider Splicer. Lay a pair of Proximity Mines in the aisle leading up from the Big Daddy to your position, then target the Spider Splicer with Hypnotize 2 to befriend it—befriending the Spider Splicer makes it wait to attack the Big Daddy until you fire the first shot.
Add some Trap Rivets and or Trap Spears to the area, then get the Research Camera rolling and swap to the Speargun. Stand atop the aisle, in the back of the theater, and fire a Rocket Spear at the Elite Bouncer to get its attention. The Spider Splicer leaps into action, buying you some time to fire off a few more spears. You may be able to finish the Big Daddy off with Armor-Piercing Rounds and Incinerate! 2, but more than likely, your enemy eventually rampages up the aisle towards you. Step out of the way of its Drill Dash, and switch to the Launcher. Hit the Elite Bouncer with Electro Bolt to immobilize it, then finish it off with a couple of Frag Grenades.
Little Sister Encounter
Gather #1: Inside The Triton Cinema
The first Gather is in the theater, right where you first saw the Little Sister. There are a lot of entrances into the theater—too many for you to efficiently cover with Trap Rivets, Trap Spears, and Mini-Turrets to defend them all. Focus your Trap Rivets near the door at the back of the theater, leading in from the lobby, and near the two doors that flank the stage. Place a Mini-Turret near the stage and add a few extra Trap Rivets or a Proximity Mine to the area beside the corpse. Set the Little Sister down and move towards the stage; the Splicers attack once the screen goes up! Let your defenses take out the Leadhead Splicers that attack, and have a charged-up ball of Hypnotize 2 ready to fling at the first Spider Splicer you see. Get one of these guys on your side early to make the whole Gather go much easier!
Gather #2: On the Balcony in Triton Theater
Climb the stairs to the balcony in the theater and quickly befriend the Spider Splicer standing near the edge. Move quickly to take advantage of your new friend’s strength and set the Little Sister down on the corpse right away. Lay some Trap Rivets near the aisle and string up a few Trap Spears on an angle over the seats near both entrances. Some of the Splicers attack from the hallway upstairs, while others clamber up from the seats below. Place some Trap Rivets on the center of the ceiling for the latter. Make use of the Fountain of Youth tonic (if applicable) and stand in the water pooled at the end of the balcony while defending the Little Sister. Befriend another Spider Splicer once the first one perishes, and use Electro Bolt to zap the water along the front to electrocute the Splicers as they make their way towards the Little Sister.
Move up the stairs inside the Triton Cinema to explore the rooms near the projection booth. Not only do you find a massive munitions cache in the office beyond the Security Camera, but you can also obtain the Extended Reel tonic in the projection booth at the end of the hall.
Exit the theater and make your way west to the south end of the Promenade. The Promenade contains a number of items and ammo stashes to collect, as well as an Audio Diary sitting atop the piano in the corner. Be sure to collect the Proximity Mines behind the counter on the south side of the main room.