They plumb deeper into Hephaestus -- down stairs that must be leading into the heart of the earth by now; through a tunnel lit red, crossing the rock and sand of the seabed, passing by pillars of rock that spew hot black smog into the water.

And as they go further, Jack still can't put into words why it is he feels so miserable.

He likes fetch quests. Searching for things and then finding them is rewarding, he's good at it, that's how it's always been. And he really wants to find a sub to get out of this horrible place. So why does this feel so much like a chore? It's unfair and it's preying on his mind; he's had more than enough mysteries and nasty surprises for one accelerated lifetime.

He's tempted to ask for that pit-stop after all. At least there's one thing guaranteed to lift his mood and he'd really like some right about now.

But before he can make up his mind to say anything, the radio crackles, and a voice comes out.

"Jack? Are you here?"

It's Tenenbaum. It's Tenenbaum, and she doesn't sound as if she wants to chew him a new one. Jack stops walking, stares wide-eyed at Sinclair for a moment, then grabs the radio in his free hand and starts talking into it. (And he puts his back to the wall as he does, pretty much by instinct.)

This time it's excitement and trepidation making his hands tremble.

"Doctor Tenenbaum? I'm here? Did... did you........"