This trophy will become missable when you first meet to the Voo-Doo lady.
You will be able to hear the patients being treated by knocking on the doctor's door. The building can be found attached to a bridge for you to cross.
The first time you knock on door is when you first arrive on the island after punching the man in the nose.
The second time you knock on the door is after you started the bar fight in Club 41.
The third time you knock on the door after finding the buried treasure with Doro.
The final time you knock on the door after you knocked Winslow off and becoming captain of the ship.