Tuesday marks the beginning of the end for Person of Interest, CBS' examination of the benefits and dangers of artificial intelligence. Star Michael Emerson teases the fifth and final season as "the battle to the death of the two artificial super intelligences": the more human-like Machine, and the calculated, pragmatic Samaritan. But this time around, the solution may be in the hands of the humans. Who will prevail?

The ominous opening minutes of Tuesday's premiere, a flash-forward to what is presumably the series' conclusion, indicate that not everyone will get a happy ending by the time all is said and done — and some (the Machine included) may not even make it out alive. But there's a lot to cover before we get to that point, starting with whether or not Finch (Emerson), Reese (Jim Caviezel) and Root (Amy Acker) can successfully reboot the Machine, which was looking quite banged up at the end of Season 4.

It's a safe bet that the crew is able to get the Machine back up and running — but at what cost? "The writers ... take that idea of having to try to reconstitute a very large and complicated system, and [explore] what might go wrong along the way to rebooting it," Emerson tells TVGuide.com. "In the course of being hyper-compressed, as it was at the end of Season 4, some damage or crossed wires, if I can use that term, have occurred. And they need to be dealt with before the Machine can be useful again. ... And of course, it creates a forum for a philosophical battle between Mr. Finch and Root, because they're collaborating on the reboot and she likes a more powerful, less ethical enemy for Samaritan. She wants it just to go for it. ... But Mr. Finch will try to hold onto the original concept."

Person of Interest producers haven't ruled out a reboot

The dilemma will be preserving the Machine's "goodness," while still programming it to be a formidable enemy for Samaritan. But whether or not those goals are mutually exclusive remains to be seen.

"We've always seen that Samaritan does what it wants to for its own purposes," executive producer Greg Plageman explains. "It's programmed for a certain goal, and whether or not humanity becomes collateral damage isn't necessarily its concern. What we've always come to believe about our Machine, given that Harold Finch was the initial coder of the Machine, is that he would never allow it to harm anyone, or never proactively do anything adverse to a human being. Those themes become more emergent as the season goes on."

"But the interesting part," Plageman continues, "is our Machine's been losing. It's been getting its tail kicked by Samaritan for so long. The question becomes for Harold Finch, if he's able to reconstitute his machine, what is he going to do differently this time? And how is he going to confront Samaritan when it seems so dominant and so formidable?"

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As the season progresses, it's likely that Finch will be faced with a decision about whether the Machine will ultimately need to be destroyed for its own good, or the good of mankind. As we saw at the end of Season 4, losing the machine "would hurt him worse than he can imagine," Emerson admits. "He can't deny that he feels a kind of paternity for the thing, and the thing is dear to him. It's innocent. It's obedient. It's super powerful and dangerous, but it is his child on some level. I think that's an interesting theme that the show has had the nerve to explore with some nuance, I think. ... Mr. Finch, who's always claimed that this was just a machine, this was just a tool for us to use. And yet he has gradually fallen under its spell a little bit."

Season 5 will also mark the return of Shaw (Sarah Shahi), in Episode 4. But like the Machine, it's unclear whether she will be back in her original form, so to speak. "Catching up with her and finding out what's been happening to her all this time, it's really, really exciting," executive producer Jonathan Nolan tells TVGuide.com. "What has been happening to her? What has Samaritan been doing to her? And it's in the tradition of some of my favorite mind-bender shows, like the original series of Prisoner from England in the 1960s." Shaw's return kicks off a series of "sort of paranoid, fantasy-inducing episodes, where you realize the degrees to which Samaritan will go to try to break Shaw," Nolan teases.

With just a 13-episode order, CBS is burning through the final season of Person of Interest with two episodes a week, airing on Mondays and Tuesdays beginning May 9.

"These last 13 episodes are gonna run like a freight train," Plageman promises. "[Fans] will be richly rewarded if they stick with it to the end."

Person of Interest returns Tuesday at 10/9c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)