Go all the way to your left until you see the bus. Talk to the old guy with the mustache. Then another guy will come out asking you to replace him and he gives you a few things to help.
Now you can enter the tunnel behind the bus. You might want to take out your flashlight. Head over to an old truck and you'll see a zombie! Try to get past them. Keep heading left and jump over the zombies. Once you reach an oil truck pick up the keys and continue. Once you reach a green "Dorf Bean" car use the keys. It fits!
Turn on the lights and get out of the car. Then click the crank on the bottom of the tow truck. It will scare away the zombies and you'll be able to enter Financial District. Then go all the way to the top until you reach a crane. Use it to pick up the bar with an open lunchbox on it. Pick it up then carry it to the top. Click on the lunch box and you'll find a subway pass at the bottom.
Now get off the construction site, go left and you'll see a subway sign.
Go down and to the left where you will reach a pass scanner. Use your subway pass. Once you get through go left and there will be a light bulb above you. Click on it. Now leave the subway and enter the smoothie shop where you will simply grab a pamphlet. Then leave and go all the way left to Shady Side Apartments. This is where Dr. G. Romero lives. go on the left side of the building and keep jumping straight until you reach a door. Room 7 (my lucky number) is his apartment. Click on the sticky note on his computer and leave. There's a lot of other things you can click but there's no point. Go into room 5 and jump on the shelf to get the bolt cutters. Then go over to his fridge and grab a clue. Enter room 1 and there is a person watching TV asking you to "come chill". Sort through his trash can until you find Valley Rain soda. Then grab the camera to the right. You can also play his video game if you want. Just click behind the TV. Go left and you see a Chinatown sign, go left. Sorry for the loss of pictures, I'm not able to take a screenshot for some reason. You will see some places but keep running to the Karaoke Bar. Enter. Keep going right on stage and you'll see D.J. Saturday Nite! She's trapped and asks you to help. Shine your flashlight up at the disco ball which will keep the zombies for a while but not enough. Go t the second Disco ball on the right which will scare away a zombie. Then you can turn the disco lights on. After the zombies leave ask D.J. the third choice and she will leave. You notice that she left her computer running. Click the find my phone in the corner. User: doctor Pass: awesome. You will see where his phone is. Before you leave don't forget to grab the papers on her desk.
In this picture I went on the roof of the big red building, jumped onto the lanterns, and used the light bulb to scare the zombies away. Then I entered the manhole. You will now be on top of the train, or you should. Try again if you fail. Enter the train and go all the way to the right where you'll reach a lever.
Pull the lever and the train will go right. Exit the train and there will be a ladder leading to the secret bunker. Enter the bunker.
When you enter go down and to the phone on your left. Call Dr. Romero's number and it will fall out of the cage with a zombie captured in it.
You will also have another clue. You can look at the short video diaries on his cell phone. Click on the chart. Eventually you should get this:
Blueberries were the cause! That makes sense, they're the color of blueberries. Then coffee will automatically start pouring. Grab it. Now go back to Chinatown. Go all the way left and you'll see the Wharf entrance but its locked. Use the bolt cutters to get through.
Go left and you'll reach a room that says DO NOT OPEN until 2000 and enter. You will see a guy in a green outfit. Talk to him.
If you give him a cup of coffee he'll give you a key card. He says he will shine the spotlight so you can climb the crates. Go ahead and climb, eventually you'll end up here:
Use the key card here and you will see shipments.