From the starting pool, hack the door control. Head right and follow the long hallway to find only this vending machine. Hack it to ride a secret elevator.
As you follow the path, grab this easy-to-get Cave Painting.
Hop across the water to snatch the cell, and climb the ladder. Plug in the cell to power up the elevator, and have your whole team ride to the lab entrance.
Once you enter the main building, climb the ladder and hack the control panel. Ride the elevator down and back again to survey the missile, and the door next to the ladder will open.
Be careful around the laser, but when it starts moving away from you, run to the control panel. Hack it to have the laser eradicate the nearby scientist. Pick up the key he drops and insert it in the first room.
Now head into the room to the right of where the missile was. In here is the admin terminal. View it to see what codes are associated with what day of the week - they are generated randomly, and they are important!
Now hack the elevator control and ride the elevator down. Continue descending to the bottom left room of the building, the cafeteria.
Hop to the wet floor sign to grab it; if you walk by, you'll slip. Grab the sign and climb back up a ladder.
Climb back to level one, the one with the yellow-striped wall. Go left and climb the ladder. Place the wet floor sign in here and hack the computer. The other scientist will run at you, slip by the sign, and slide off the edge near the ladder. This also loads the warhead into the missile. Drop down and grab the second key from the now-still scientist and insert it in the main room.
Now head back to the cafeteria, this time all the way to bottom. Grab the Cave Painting, and then look at the blackboard. Take note of the food that's listed.
Now head to level two, the green-striped one. Head right and check the bulletin board. This has the weekdays listed out, with food specials listed alongside them. Match up the food that was on the blackboard with the day of the week. Then, match up the day of the week with the appropriate four-digit code from the admin terminal (we told you they were important!).
Head to the lower level and go right. Take the lower path to find a Cave Painting, and then hop up top. Enter the appropriate four-digit code and hit the green button to unlock the security door that guards the knockout gas.
Grab the knockout gas and head back to the room with the bulletin board on the far right of the room is a vent. Plant yourself near it.
Switch control to another character, and head to the room with the admin terminal. Climb the ladder on the far side of the room to reach some HCAV controls.
Activate the HVAC controls, and switch back to the character with the knockout gas. With the HVAC controls going, drop the knockout gas. It will travel through the vents and knock out the armed guard on level one. Grab the key he drops and insert it in the main room.
One last time, head to the cafeteria. Fish through the bowl of fruit on the table until you get a bunch of bananas.
Head to the room the armed guard was protecting, and a monkey will scamper out. Feed him a banana, and then use the bunch to make him follow you.
Lead him to the only room you haven't visited yet, and he'll hop into the missile guidance system.
With all pieces in place, head back to the main room. Activate and hold all three keys to launch the missile.
With the missile launched, take the elevator back down and exit through the newly opened door.