Desmond gets up, types numbers into a computer and then goes about the morning, washing dishes, checking laundry, and working out on an old style exercise bike. He injects himself with some kind of prescription medication that has the numbers on it. He hears an explosion.
He grabs weapons from a vault, turns the lights down, and looks through a scope. He adjusts mirrors that go through long pipe-like hallways. We see a mirror pointing upwards and zoom in to see the reflection. It's Jack and Locke holding torches, staring down into the blackness of the blown open hatch. Desmond grabs some guns.
Desmond takes Locke hostage (Ep: 2x1, Man of Science, Man of Faith).
Desmond pulls a gun on Locke and Kate.