The Last Of Us Walkthrough Part 58 – Chapter 9: Lakeside Resort (Defending Against The Infected)
The first wave is not too hard. The boards are all intact and there is plenty to protect you. It is mostly Runners which you want to gun down quickly. They will approach from both sides of the building so you need to check the opposite side frequently. The more boards you can keep up the more effort the Infected will need to expend later to get at you. Deal with whichever lucky ones manage to get in then reload.
Between the first and second wave David will start moving a cabinet in front of some of the windows. Get to the other side of it and help him get it into position. Also take some time to check the corpses on the floor for more Rifle ammo. There is no shortage of it to be found and David will help you out with some if you get low (he will also have a spare Health Kit or two that he will give Ellie in dire emergencies). After the cabinet is in place the next wave will start.
This wave is fairly similar but there are 2 Clickers in it. Target them immediately and take them out as soon as you can. If they get into melee range with Ellie, like with Joel, it is an instant kill. With them down, finish off the Runners that came with them. They will come through the unblocked windows so turn your attention toward them and start shooting carefully for lethal shots. The runners will close in with fair numbers. Remember that Ellie has a knife and as long as she has good health she can take on a Runner to get a quick kill. This can be useful to save a shot or two of ammunition.
When the assault is over, David will leave the room and go for the back door. Follow him through it and up the stairs. David will go and block the stairs that he and Ellie took up. All you need to do is shoot whatever infected get onto the stairs so they do not make it up to the top. Check the desk to your left to see if you can find any ammo in there. After that just follow David again into the next room.
Once inside go over to the right and look around quickly for some Crafting Items. Catch up with David after you have grabbed those items. Be warned there are a total of 4 Clickers in this building. Save your ammo for this fellow alone. If possible, use David as bait and then stab them with Ellie's knife.
Follow David through the machinery and over to the stairs on the far side. Follow him on the catwalks above the machines. Hop the barricade and the walkway will collapse underneath Ellie. After she gets up and into cover, start on your way forward. Look around the corner to your left and take out the first Clicker either with a gun shot or well aimed bow shots. It is entirely possible to get most of the Clickers from this area, it just takes patience and some luck.
After you get the pair of Clickers go over to the right and look down the opening there. You will see a Clicker there you can pick off. Head down to the corpse after and check it for goods. Turn to the left after that and drop through the hole in the floor.
Go on forward and over to the left. Grab a brick and get to the front-left portion of this area. There is a Clicker over to the right. Throw the brick at it to stun it long enough for Ellie to rush in and knife it. Now look along the left-hand wall to find the ladder leading up and out of this section.