The gunshot rings out loud and clear, and the world seems to fall silent in its wake.

"We're too late," John whispers. Distantly, he can hear Shaw swearing.

The payphone on the street corner starts to ring. The shooter is long gone by now.

After exchanging a look with Shaw, John holsters his weapon and walks to the phone. "John?" asks Harold in his ear. "What's going on?"

"I think the Machine has something to say." John doesn't hesitate before reaching for the receiver.

He blinks and stumbles, suddenly dizzy. When he recovers, he's standing in the Library and Finch is pulling up a profile on the computer.

"It's the same number," he says.

"I beg your pardon?" says Harold.

John stares at the familiar photograph on the screen. "We already got this number. Candice Wong, thirty one years old, working on a research paper about something to do with plant sterols."

Harold looks at him oddly. "Deja vu is a perfectly normal--"

"This isn't deja vu, Harold. I was there. Her research partner put out a hit on her so he could take full credit for their work. By the time we found her, it was too late. I watched her die, and then the pay-phone rang. I picked up the receiver, and I was back here."

"Does Shaw remember any of this?"

"I don't know, Harold, why don't we ask her?"

Shaw doesn't remember a single thing. She's too well trained to let any of it show, but he knows she's wondering if he's finally cracking under the pressure.

"You're right about the hit, though," says Harold. "I've tracked a large payment from Candice's research partner going to a bank account in Switzerland."

"Do you remember where she was hiding?" asks Shaw.

John names the address, and they get in the car.

Three hours later, Candice Wong is safe in protective custody, and her research partner is under arrest.

Harold steeples his fingers. "Well, wherever your information came from, John, it was very fortunate that we had it."

John can't really blame Harold for not believing him. He isn't even sure he believes it. The memory of the gunshot - of Candice Wong's body falling to the ground - is blurred and indistinct now, like it was only a dream.

--

Six weeks later, Francisco del Rosario tricks his wife into falling off the balcony of their high rise apartment. With the mounting evidence of Laylah's depression and unstable condition, the verdict is sure to be suicide.

Lifting his fingers away from Laylah's lack of pulse, John feels cold dread settle around his heart.

"John?" asks Finch.

"She's dead," says John. "Call 911."

Distantly, he hears a phone start ringing. "Finch, are there any payphones in the vicinity?"

"One, about two blocks away."

Some of the neighbours heard Laylah's scream and are coming out to investigate. Del Rosario is still in the apartment, faking a shower.

"I've got eyes on it," says Shaw. "You take care of del Rosario."

John hears ambulance sirens approaching and slips back into the gathering crowd. He--

"The number's name is Francisco del Rosario," says Finch. "He's a defense lawyer, and he's just taken on the case to defend an accused child-molester. I'm pulling up the list of alleged victims now."

"Don't bother," says Shaw. For once, she sounds almost… surprised? "He's going to throw his wife off a balcony and make it look like suicide."

Into the resulting silence, she adds, "Also, I think I owe John an apology."

Once they've located the mind-altering drugs Francisco del Rosario has been feeding to his wife and reported them to Carter, Finch assembles John and Shaw in the library.

"So you're saying the Machine has developed the ability to turn back time?"

"It's the only rational explanation," says Shaw. "I answered the phone and I was back here, at the start of the case."

"It's hardly rational," murmurs Finch. "I'm not even convinced it's possible according to the rules of physics."

"Do you think maybe Root…" John starts.

They contemplate that in horrified silence for a moment.

"I'll talk to the Machine," says Finch. "See if I can get an explanation out of it." He winces. "I'm hoping it won't use quotes from Back to the Future."

"Just relax, Finch. Maybe it will be Star Trek," John suggests cheerfully.