Larissa informs you that the leader of the Disciples, Victor, mentioned the bomb which supposedly killed Angel's former-self while at a strip club. He's at the Disciples HQ, so we need to head there and find out what he knows. There is a jet-ski waiting for you by the dock near to where you met Larissa, so head there and get on.
It is definitely best to take the jet-ski to your destination, as the Disciples will be swarming around the roads close to their HQ. If you do take the jet-ski, once you reach the dock marked on your map you get a cut scene and will be standing on the dock itself afterwards. From there, head up the dock into the HQ itself.
Kill the first two Disciples to get some attention on yourself, at which point the rest of their gang will converge on your position. You should be secure at the pack as all that's behind you is the dock. Take care of this two guards who come at you straight away, and collect the body armor in the swimming pool if you need it.
Then, head up to the next level. You will find two guards and continue onwards. You will have two more guards to deal with on the way up the stairs to the next area - be sure to get the body armor which is round the corner on the level at the bottom of the grand stairs. At the top of the stairs you will have five or six enemies to deal with, plus a medkit to collect.
Two more gang members will be around the corner before you climb the next set of stairs. After one final set of stairs, you will come upon Victor, the leader of the Disciples. After threatening him, he reveals that the Medical Examiner was investigating Raul and Ana's deaths. Victor suggests we take out Marcelo and have the Syndicate and Assassinos could join forces.
Reward: 7,500R$