Una Baha, who is TK Baha’s niece, wants you to search TK’s cabin for anything that can be used to avenge his death. As you get close, Una says that you’ll need to access her uncle’s secret lab and you’ll find out that you’ll need to pull a switch or something to get it open. When you arrive at the house, look at the ceiling fan to see that the cord is glowing green, which means you can pull it to gain access to the secret lab.

View Full-size

Pull the chain on the ceiling fan (left) to open the door to TK Baha's secret lab (right).

Once you get downstairs, you need to five six pieces of evidence in the form of ECHOs. They are all located inside of the lockers, containers and safes, so just keep opening them all until you find all six ECHOs. With that done, Una wants you to find her uncle’s weapon blueprint, so go to the vending machine in the area and hit the switch on the side to open a secret compartment.

This will trigger a call from Hyperion, who want the blueprint for themselves. So, you have a choice to either bring the blueprint to Una, who will reward you with the Lady Fist pistol (extremely high critical hit damage bonus) and bringing it to Hyperion, who will reward you with the Tidal Wave, a shotgun that is similar in nature to TK’s Wave gun in the first game.