Ana-Lucia, Sayid, and Charlie find the grave and the balloon.
In the hatch, Locke hears a woman's voice over the loud speaker and messes with the speaker, trying to figure out what she is saying. Henry keeps talking from the armory, asking what it is. Locke tells him to shut up. The woman counts down and when she gets to zero, blast doors come down and Locke is trapped. He lets Henry out to help him pry the door open, but ends up having the door close on his leg. He gives Henry instructions to crawl through the vent to input the numbers into the computer.
The lights go out and a neon light comes on, revealing a diagram on the blast door. The blue light goes out and the regular lights come on and the blast doors open. Locke finds Henry and is happy that he didn't leave.