The not actually terrible Limitless hinges on the premise that Bradley Cooper's struggling writer character Eddie becomes really smart thanks to the mind-enhancing drug NZT. He quickly bashes out that book hed been meaning to finish, and then borrows some money from a loan shark (Andrew Howard) to set his next plan in motion making loads of cash. With the cash in hand, he heads to the stock market and makes shedloads of money. Everything is looking pretty cushty for a time, before Eddie comes home to find that the loan shark looking for him. Eddie forgot to pay him back. Trouble is afoot, and the shark ends up on NZT as well, becoming a major annoyance for Eddie. But lets just rewind a minute Eddie is supposed to be super smart. Its literally the very concept that defines the film - hes meant to be a super genius. But he forgets to pay back the scary Russian loan shark? If youre a pedant like me, your interest in the film begins to unravel at that point. Clearly, this stupid moment was a necessary evil as the film needed to make a villainous threat out of Howards character. However, in making the super smart character look idiotically stupid, the whole movie suffers.