Head through the back door of the facility to reach the street outside. A group of Spec Ops soldiers will be battling with a hoard of zombies outside. Take cover and stay out of sight of the enemies. If you are lucky, the zombies and the Spec Ops soldiers will largely take care of each other. When the victors have emerged and are about to target you, toss a grenade into their midst and blow them all up. Pop out of cover and mow down any remaining enemies in the streets to clear the area out. Leave cover and head to the end of the street. Head down to the left to find two Frag Grenades sitting on a fire engine, then turn around and head down to the main street. Follow the main street back on the block to get to the next area.
This road will lead you to the City Park. As you reach the steps leading up to the main gate of the park, search the ground to find a piece of Intel. Pick it up and head to the right to find a way into the park. As you navigate around the broken down wooden fences, search for the ammo and Frag Grenades next to the fence. Head through the hole in the wall to reach the inside of the park, which will be dark and shrouded in fog. The helicopter that Nicholai shot down on the rooftops will be lying ahead of you, obscured partially by the fog. This is where you will have to collect the EMP charges.
Head up to the helicopter to find the first of the two EMP charges lying next to it. You will be able to find it by the blinking orange light on top of the EMP. While you are near the helicopter, grab any weapons and ammo that you might want before picking up the EMP, because when you pick up the bomb a hoard of zombies will attack you. Restock and reload, then grab the bomb and dig in for the upcoming wave of enemies. Use the helicopter to keep space between you and the enemies, strafing around it for cover. Mow the wave down with your squad and head out to search for the second EMP. The problem here is that the location of the second EMP will be randomized each time you play the level, so there is no concrete location to find the bomb at during any given playthrough. The fog will obscure large areas of the park, making it even more difficult to find the EMP. Scour the area and search for the telltale blinking orange light on the top of the EMP to find it. Along the way, watch out for more zombies. Waves of the enemies will spawn every minute or so as you traverse the park, so watch your back and be sure to avoid infection.
As you search the park for the second EMP, don’t neglect to grab the Raccoon City Mascot pickup as well for a huge experience points bonus. You will find the Mascot along the right side of the park. From the entrance gate, follow the right-hand wall to reach the sewage drain with broken bars blocking the front. From here, search to the right, behind the shopping cart. You will find the Raccoon City Mascot lying on the ground in the fog.
After you pick up the Raccoon City Mascot item and both EMPs, an objective marker will appear over the gates at the exit. Run towards the gates to escape. As you approach the exit, a group of three more zombies will pop out and attack you. Gun them down quickly, and then head through the door. You may have escaped the dangerous City Park area, but you have unfortunately walked straight into a boss battle in the process. As you escape through the gates, you will approach a mansion and its large front yard. Nicholai will pop up in one of the second story windows, by the clock tower. He will be equipped with a Sniper Rifle and grenades, and you will have to fend him off. Although your squad will tell you to cover them, your main objective here will really be to deal enough damage to Nicholai to trigger a cutscene in which he retreats.
Boss Battle: Nicholai
The back yard of the clock tower will now become a makeshift battleground where you will have to fend off Nicholai and the occasional hoard of zombies. Immediately survey your surroundings and make a mental note of the different cover spots, items, and ammo stashes. You can take cover behind the four rows of shrubbery in the yard facing towards the clock tower. There will also be various safe points at the very front of the clock tower, under the windows. From here, Nicholai will not be able to hit you with his Sniper Rifle at all. Just note that he will still be able to toss grenades down from the windows, which he will do frequently, and that you will have to leave this position to refill your ammo and grenades at some point.
The crux of this boss battle is a sort of whack-a-mole game in which Nicholai will run between the four windows on the second floor of the clock tower, taking cover, popping out, and shooting you and tossing grenades your way. You won’t be able to hit Nicholai while he is behind the windows for cover. Wait until he pops out to snipe or toss a grenade before taking a shot at him. If you have a Shotgun in this battle, you really won’t be able to do much against Nicholai and his Sniper Rifle. Swap it out for anything you can, or rapid fire your Pistol instead. You can find two weapon lockers in this area, one to the right and one to the left, both of which contain Semi-Auto Rifles. These guns are probably far preferable to the weapon that you have brought along, so be sure to grab them before stocking up on ammo from the piles on the ground and the Ammo Locker. Using this scoped weapon, you can see that there are two explosive barrels conveniently located behind the far left window and the far right window. Hit these while Nicholai is nearby to deal heavy damage.
Hit Nicholai when he pops up to shoot you. Note that you can deal some pretty decent damage to Nicholai even when he isn’t visible in the window by tossing grenades through the windows. Make sure you know which of the windows he is in before you throw so that you don’t end up wasting your grenades. After you have gone through your stock of grenades, pick up more Frag Grenades from the ground all around the shrubbery that makes up the cover of the area. Finally, you will find a Green Herb in both the back left and right corner of the area.
After you deal a certain amount of damage to Nicholai, he will curse you and ring the bell in the center of the Clock Tower, calling a hoard of zombies into the yard. Backpedal into the side corner of the area, which just opened up to release the zombies. From here, Nicholai will not be able to shoot you while you fend off the zombies. Let the zombies come to you as you shoot them, and then head back out and deal some more damage to the boss. After a while, he will again ring the bell and call more zombies out. Repeat the process of killing the zombies, then head back out and attack Nicholai again. He should die soon after the second time that he calls out the zombies.