Late Checkout is a Ray Boccino mission.
Ray now wants Niko to go after Issac after the failure in the Libertonian, where Johnny Klebitz escapes with Rays diamonds and left Ray with no money, no diamonds and an angry Issac. Issac is hiding out in the Majestic Hotel with several henchmen. Inside, Niko needs to go up to Floor 31 using an elevator and find room 202, where Issac is hiding out. When on Floor 31, Niko will have to eliminate several henchmen and get up to room 202. Inside, one of Issac's henchmen can be spared because of his old age, or can be killed. The second can be found going up the stairs and can only be killed, as well as the final person, Issac. Afterwards, Niko needs to leave the Hotel to complete the mission.