1 - Close on one of those up / down arrow signs above an elevator. The red down arrow is light up.
2 - In the elevator, put arm up to hold door and look out based on someone yelling. Said yelling person is a woman rounding the corner, running towards the elevator in a big hurry. She's holding a bag, although it might not be visible in this panel.
WOMAN: Hold the elevator!
3 - The woman is now in the elevator and is pushing the close button repeatedly. The man smiles at her rush. They are framed by the elevator doors (which are probably starting to close).
MAN: You're in quite the rush--
4 - Reverse angle, now inside the elevator. From this angle, it's clear that the woman has a pistol tucked into the back of her pants' waistband. Also, if possible, show that her bag is stuffed / overflowing with hospital supplies. Part of me is thinking stethoscopes, bandaids, and maybe needles, but I have to admit that pills would probably make a lot more sense (although something like morphine could fit the bill, too). The man certainly notices the former and possibly the latter. Either way, his smile fades. She looks over, awkwardly realizing what's happened.
MAN (trailing off): ...aren't you.
5 - Still in the elevator, the two look at each other awkwardly. The woman pulls down her shirt to better hide the gun.
6 - Repeat panel 5.
MAN: Did you just rob a hospital?