He looks up at the floors above them, then back at Sinclair, not buying it.

"But we're about to go up."

And then they'll be doing one more thing, and then another thing, and then the next five objectives, and yeah you're starting to understand why Jack had barely slept when Sinclair found him. Besides the splicers.

(If Sinclair's familiar with the combo of caffeine, adrenaline and sheer sleep-deprived insanity, he will be intimately familiar with Jack.)