A cutscene shows that after a call from Moira, Barry comes over with a speed boat. Before he gets off, he encounters a small girl that's about ten years old named Natalia. After the introductions this is where they start.
Outside the island[edit]
Barry's story begins outside of the island facility. The gate is blocked and the stairs to the left of them have crumbled, so simply follow the coast until you see a barrel. Walk toward the wall after destroying it and climb the ledge. Follow the path until the pair spots a group of spiders. Knife them all so that Natalia doesn't get hurt and climb the ledge. Continue to move forward until Natalia takes notice of some spiders. After they're out of the way, head around the boulder or up the stairs and Barry will point out the gate in the way. Interact with it to make your way into the facility.
Being stealthy 101[edit]
Collect the red and green herbs to the left before moving further in. Head right at the turn and Natalia will warn of some "monsters." A small group will attempt to ambush you past the blue door, so have your gun ready. Jump over the table up ahead and interact with the large blue doors to open them. Natalia will then warn of some more enemies and the game will prompt you to switch characters; Natalia has the ability to sense all enemies in the area, even through walls, and is especially undetectable when crouching. Use her sense to spot all enemies in the area and have Barry take them out using stealth kills to conserve ammo if possible. Perform another stealth kill at the top of the stairs and carefully make your way to the end of the room. To the left is an opening for the upper ledge, and across from it is a box that Barry can lift. Bring it over and use it to climb up to the second level, then interact with the gate at the end of the hall to continue forward.
Double the puzzle, double the trouble[edit]
Pick up the Control Room Key hanging off of the cabinet and go around it to find a small opening in the wall. Switch to Natalia and have her crawl through it. Pick up the brick and use it to kill the zombie in your path before unlocking the door for Barry. Switch back and push the crate out of the way. You should recognize this next segment from Claire's story; you can't head through the doorway on the right and drop down since Claire and Moira turned the power on, so instead move forward and head through the door on the left. Continue through the door at the end of the hall and be aware of the enemies in this next area. Open the next door and prepare for some more zombies as you go down the stairs to the left. There's an opening in the wall that Natalia can crawl through; have her pull the lever to shut off the power and backtrack to the doorway on the right mentioned earlier and drop down. Use the workbench if you need to before continuing through the next door.
If you didn't set off the fire trap in Claire's story, Barry and Natalia can simply walk through and continue forward, but if you did set the trap, you will now have to go through an extra step in order to get past the trap without being burned alive. Turn toward the prison area and head up the stairs. Use the Control Room Key to get into the back room after disposing of some rogue Afflicted and pull the lever to open all prison cells, but be warned: depending on the difficulty, this will free many enemies. Have Barry shoot them all out of the way before sending Natalia to the last cell on the right. Follow the footsteps and drop down to the grating below, then turn around and drop down once again onto solid ground. Make your way to the end of the path and climb up the ledge to find another crawlspace. Crawl through and interact with the fire trap to turn it out of the way, letting Barry pass before turning it back and leaving the facility by interacting with the gate.
Through the alternative path[edit]
Follow the same path that Claire and Moira walked until you come across the now-inaccessible bridge. Turn to the left to find a door with a crawlspace next to it. Have Natalia crawl through and pick up a brick on the other side to bust the lock. Continue to follow the path and interact with the ledge to drop down. Up ahead is a set of lumbers and a cutscene showing off a new enemy. Head through the cabin and interact with the double doors at the back. Natalia will get spooked but there isn't anything in the cabin just yet, so continue to work on the doors by tapping the button onscreen. Eventually, Barry will be forcibly interrupted and you'll have to defeat the Revenant. Shoot at each of its limbs, including the head, until you find a weak spot, indicated by an orange bubble, and shoot at it to kill it. This is made much easier with a second player, as Natalia can sense the weak spot while Barry fights, but it's doable with trial and error. Interact with the doors once more to reach a forest area.
Journey to the communication tower[edit]
Follow the lights toward the right of the map and deal with the few Revenants that pop up. Head past the house in the clearing and interact with the doors to make your way into the next area, when Barry will start mentioning the new virus' uncanny similarities to Uroboros. Knife the lock on the gate and interact with the ledge to drop down. Kill the next couple of Revenants by throwing the firebomb bottle that's conveniently laying around and head through the next set of doors. Drop down from the busted staircase and interact with the chained gate in the way to trigger the arrival of some Revenants. Head toward the fence that they broke down, past the locked wooden door and around the debris to gain entrance to the house. Turn on the generator inside and backtrack to the cabin on the other side. Find the entrance to the right and beware the Revenants as you walk through all doors inside. Turn left at the end and the door there will take you outside, where you can pull the lever to activate the crane. Head through the newly-opened gate and finally, toward the radio tower.
Inside the building, interact with the controls to trigger a scene, leading into Claire and Moira's Episode 2.