As soon as the chapter begins, run forward and toward the car. Look for a dead body next to it and claim the El Diablo nearby. With that in hand, head further along until you reach the dam. Go to the right side of the water and up three flights of stairs, using a Shiv to crack open the nearby door. If you aren't sure exactly where this is, it's next to the wheel that you have to crank to build a bridge. Once you're inside, do some crafting and then gather up all the goodies laying around.
Exit the room and take a right, then hop over the railing to your right. Jump into the water and dive under to see an icon near a sunken structure. Swim to the icon, releasing the wooden pallet and then taking it to Ellie. As always, use the pallet to ferry her across to the other wheel. When she's up there, swim back to the other side, then use the now completely lowered bridge to cross over to Ellie's side.
Make sure to check the entire area for loot, and when you pass under some debris, check all the buildings for more. Take note, if you missed the El Diablo, you will now find it tucked away in the same shack that has a map on the wall. When you're done exploring, walk up to the gate and interact with it to trigger a cut scene.
When the scene ends, head into the yard and go about the business of petting the horse, then follow Maria up the stairs and into the plant. You'll get another cut scene, but when it's over start following Tommy and making your way through the plant.
After going back outside, crossing the dam and passing by a dog that you can pet, you'll go into another building. Be thorough here, as you can acquire Tools Level 3 as well as Training Manual: Smoke Bombs Upgraded. Just to the left of that stuff is another crafting table, so loot the room first, then spend a few moments upgrading your gear.
Tip: If you don't see Tools Level 3, you've already picked them up in a previous chapter. They will only appear here if you're missing them from before.
Exit the room and follow Tommy to watch them try and restore power to the dam, and when that's done, follow Tommy into another room for a brotherly chat.
When the cut scene ends, take cover with Tommy, then fire up Joel's focused hearing and start clearing out the attackers. It's actually the perfect time to try out your shiny new El Diablo, using the scope to score headshots on the bad guys who are behind cover. If that fails, just move cover to cover and take them down with the Shorty or Shotgun. You could go with a Molotov or Bomb when you encounter large groups, but you should be able to manage without.
With the first room clear, head back into the room where the crafting table was, then back out to the bridge where there will be even more attackers. Don't bother crossing onto the bridge just yet. Stay in cover and use your Hunting Rifle, which is especially useful if you have the upgraded scope that allows you to zoom in. When the bridge is clear, continue moving along through the plant in an attempt to get back to Ellie.
Tip: You can use the bottom of the bridge as a flank route, allowing you to get behind your enemy and use some melee attacks to save ammunition.
When you enter the next building with Tommy, work on the guys below you from your height advantage. The last few attackers are in the next room, which provides a great opportunity for a Smoke Bomb, allowing you to rush in and finish them off with some melee. Although there is more combat ahead, the extra ammunition isn't necessary, just really handy as an option.
With the situation under control, you're in for another cut scene, but when it ends you get to ride a horse while chasing after Ellie. For the first part of the trip, just follow Tommy, feeling free to jump down and search for supplies any time you'd like. When you reach a dead end, turn around and take your first left, then follow the horse tracks to the bottom of the mountain and through a small body of water. When you jump a log near a truck, it's time to get your fighting boots on.
There are a set amount of bad guys here, and we found it was most beneficial to work up the right flank in a counterclockwise direction. You should have no trouble using Joel's focused hearing and performing a couple of stealth kills. If you're loaded up with arrows for your Bow, now is a good time to use them and not give away your position with every short. Just be sure that as you kill bad guys, you pick up loot off their dead bodies and from the structures in the area.
When Tommy gives you word that everyone is down, head back to the horses and get back on Ellie's trail. Just follow Tommy until you reach the ranch, then enter the empty house and start searching for loot. Try to find as much as you can before talking to Ellie, and even take a moment to catch up on your crafting and reloading.
When you're ready, go talk to Ellie and enjoy one of the most intense cut scenes of the entire game. After it's over, however, get back to work killing some bad guys. It's fairly simple to do since it's all narrow hallways, stairs and doors. Just keep a position of advantage and waste them when they get close. Of course, if you want to be all James Bond, go ahead and choke everyone out, then pat yourself on the back. You can expect a total of two bad guys on the top floor, and three more wandering around below.
Once the battle has ended and the house is looted, head back outside for a chapter ending cut scene. Go grab yourself a drink from the kitchen, then let us help you move on to Chapter 8: The University.