Now that's a little less quiet. Sinclair jumps as the first clang of the wrench hits the wall accompanied by a fair amount of angry grunting and cursing. And it would be a little more along the lines of run-of-the-mill splicer behavior if it didn't sound so much like...

wait.

Sinclair pulls himself out from under the desk, hoping the violent noises will cover up the sound of moving water, and looks around the corner.

And he'll be damned if that isn't Jack. (spoilers: he might be damned anyway.)

"...Kid?" he says, standing up. "Hey, kid." A little louder in case he didn't hear.