Tony tells Burke, who apparently didn't hear Tony's end of the conversation, that Kiefer's on his way, and that they'll figure out what to do about Henderson when he arrives. "There's nothing to figure out," Burke says. "This guy's cooked." And then Tony pistol-whips Burke from behind, sending him unconscious to the floor. So Burke has a glass skull. Got it. Tony turns to Burke's open case of torture goodies, selects a vial, and fills a syringe. He holds the needle poised over Henderson's sternum, but when his own Pulp Fiction moment arrives, he can't commit the deed. He ends up just standing there, holding the syringe, looking disappointed in himself. Which is of course when Henderson's eyes pop open. Taking in the situation at a glance, he grabs the needle and forces it into Tony's chest. Nice one, Tony. And nice one, Burke. The idiot not only went too far, he misdiagnosed his subject, and of course completely failed to restrain him. Burke is the worst torturer ever. Roger. Tony drops to the floor and commences dying. Henderson sits up, pulls out his IV, grabs Burke's gun off the bedside table, checks the clip, and heads on out of there, barely pausing to rub his aching head. Now that is fucking bad-ass.
He apparently took a different exit than the one Kiefer is just arriving at. Kiefer immediately spots Tony on the floor, still holding the empty syringe that's killing him. "I couldn't do it," Tony manages. Kiefer says it's all right, and pulls Tony up into his arms, hollering for help. Too bad Tony knocked out the only surviving doctor in the place. Kiefer begs Tony to hang on, but Tony's not in the mood: "She's gone, Jack," he says. And then it looks like Tony is too. Kiefer holds his friend tighter, giving Henderson a nice, juicy head start while his face gets all weepy and lemony. Sure, Kiefer just had a particularly bad hour, but he should consider himself lucky that Henderson didn't bother to blow up the room behind himself this time.
So then the clock ticks down to 7:00:00. And if you think they're going to do the silent clock two episodes in a row, guess again. This was the cause of much uproar on the forums, that Edgar got the silent clock and Tony didn't. I choose to interpret it as Tony not being actually dead. At least not for good. And y'all are going to feel pretty silly when he Buffys out of his grave along about Season Seven, I'm thinking.