Last week on Limitless, Brian (Jake McDorman) was rewarded for passing Eddie Morra's (Bradley Cooper) loyalty test with his own personal stash of NZT pills. What could go wrong, right?

Plenty, as Brian will quickly discover. "If you have NZT and you have acquired immunity to it, it's very hard not to use," showrunner Craig Sweeny tells TVGuide.com. "Very quickly, Brian gets down to the last one of those pills over the course of the next few episodes."

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But it's not a physical addiction that compels him to take the drug, Sweeny notes. "The way Brian's experiencing NZT is different than the way most of us would, because he has that shot from Eddie Morra," Sweeny explains. "It's not that he needs to take those pills or that final pill because he is physically compelled to do so or because he's servicing a powerful physical drug addiction. It's more so that, when you have a pill that can solve any problems - life is a continual series of problems. So, how do you decide, is this big enough? Can I face this one on my own? And does Brian have the confidence to face problems on his own without NZT?"

Presumably that means that Brian will have to return to his source to get more. Does that mean Cooper will be making more guest appearances? It's looking likely. "Without officially saying anything," Sweeny teases, "I would say that I would be very, very, very surprised if we don't see Eddie Morra again."

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