- "Jesus officer, where'd you come from? Pearl Harbor?"
- ―Marvin to an injured McClane who just fell down a flight of steps. [src]
When McClane was in the basement and shut off the record player, Marvin comes up from behind and startles him. After proving who he is and that he is a janitor at gunpoint, Marvin shows McClane the blueprints of the annex skywalk at the new terminal, which is the nice place for a bottleneck ambush. At McClane's request, Marvin shows him to the ventilation duct that would get him to the annex skywalk, which allowed him to save Dulles chief engineer Leslie Barnes in time from Colonel Stuart's men.
Later, McClane returns to Marvin to help him get to the pilot's briefing room after he was denied access. Just as Marvin was about to help him find it, McClane finds the encoded radio that mercenary Miller dropped with the code still punched in after Garber and Stuart speak to each other and was ecstatic to find it. Marvin says he found the radio next to the luggage conveyor belt. After hearing General Ramon Esperanza calls out a mayday to Colonel Stuart, McClane tells Marvin to show a shortcut to the runways so he can get to Esperanza when he lands.
Afterwards, McClane, bruised and injured, tumbled down the stairs near Marvin's place and he comes to him. McClane tells Marvin to take him to the airport police station quickly. Marvin drives the luggage cart fast from the terminal to the police station. Marvin watches as McClane warns Captain Carmine Lorenzo that Major Grant and his men are in league with Stuart and Esperanza. He also witnesses McClane firing blanks at Lorenzo to prove that Grant and Stuart are working together. After McClane and Lorenzo scrambled to head for Hanger 11, Marvin cheers on while saying, "Just like Iwo Jima."
After all the planes landed safely, thanks for McClane using the burning jet fuel from the destroyed terrorist's plane, Marvin arrives in the cart to pick McClane and his wife Holly and takes off with them in tow.
- Judging by his bizarre and random references to it, Marvin apparently served in World War 2. This would also account for his rather strange behavior in general.