The Last Of Us Walkthrough Part 68 – Chapter 10: Bus Depot (Underground Tunnel)
Head over the Grassy hill quietly and carefully. There is a Bloater wandering in that area with more Infected ahead. Time to get into a better position just to deal with things. Watch the Bloater a while to get a sense of how he is moving. When he is farther away head over to the maintenance building you see on the right just in front of the truck. Climb up onto it and head onto the far end of the semi. Be sure to take a moment to set at least 1 Nail bomb on the rooftop of the maintenance building. It will help sooner rather than later. It is time to start, quietly, dealing with the Infected.
Use Listen Mode to find the nearby Runner. There is likely one just standing around below you. The longer you can keep quiet, the better. Use an Arrow to take him out. If you are very good with the bow and arrow, look to the right of the car from the top of the Maintenance Building. You will see a second Runner standing around. Pick him off as well. The other strategy is to lob a brick between them, wait for them to move in toward it then throw a Molotov on them. There is one more running ahead on the left-hand side of the tunnel by a pile of cars. He can be picked off but it is a tricky shot as you cannot see the head very well.
If you use the Molotov strategy then the Infected will begin to converge you on starting up a proper fight. Stay on the roof and fight them off using your various weapons. Being on the roof of the maintenance building will slow them converging on you. Take advantage of this and cut them down quickly with your weapons, be it melee or guns. When it is all done, be sure to loot the bodies. The Infected can carry ammo and there is always need for that.
After the fight head over to the left-hand side of the area. Look along the walkway to find more Crafting Items. Now cut across the tunnel and look for the bus. Head for the walkway by it and hop over it. There is likely some ammo there and just ahead you will find more bottles. As you got to the ammo, more Clickers should have appeared in the watery area by you. This means you need to move quietly and slowly. There are even more to be found in the room to the right but there is also a training manual in this area. Head into the room first as it will not take much to deal with.
In this room you will likely find a melee weapon, Parts and Crafting Items. Turn to the left, toward the stairs and look up: 3 more Runners. Lob a Brick or bottle between them then follow it with a Molotov. This will quickly kill them all off. Now head down the corridor they were in to the end of it. You will find some shelving with Parts, Ammo and Crafting Items. Head back the room you started in now. Time to start chipping away at the Clickers and the Runner in the main area.
Start by moving up to the railing and watching the nearby Clicker. As it turns away, shiv it. Duck behind the car and start watching the next nearest. It walks a simply patter nearby so watch it. Move to the nose of the car and when it gets close, shiv it. Now, you can use an Arrow to quietly kill the nearby Runner with a careful shot. After that head on forward to deal with the rest of the runners on the other side.
With the Runners dealt with then head over to the left-hand side and look for the trailer that is sitting on the edge of the water with a red lion head on one end. Head over to the Left-hand side of it and climb up it. Look on the roof of this trailer to find the Training Manual for Bombs #2: Shrapnel. This will double the explosive radius of your nail bombs. Look over the other side of the trailer and take a note of things. There is a lot to deal with.