The magic pill, NZT, is an experimental drug taken by the main character (Eddie) in the action thriller, "Limitless". The movie is about the series of fortunate and unfortunate events following Eddie's encounter with the pill.

We all heard the myth that large part of our brains remain unused. What the pill does is to allow its users to fully exploit all faculties of our brains. So after Eddie took the pill, his intellectual power was tremendously expanded. He was able to finish a novel in 4 days, learn a new language effortlessly, acquire new knowledge 100 times faster than Einstein could, and even become an god-like invincible stock trader.

There's always a catch, of course. The intellectual enhancement is only temporary. When NZT wore off, users would revert back to their dumber forms. Things can get ugly when a user stopped taking the pills, the withdrawal could cause severe damages to both the brain and the rest of the body, leading to death (or brain death).

The ending is most intriguing. After some extraordinary events, we see Eddie was now running for president of United States. His former boss, a relentless multi-billionaire, Warren Buffett kind of guy (only eviler), revealed to Eddie that the lab that made NZT was bought out by him. He threatened to cut Eddie off from the only supply of NZT, unless Eddie did him some dirty favors after getting elected to be the president.

That didn't scare Eddie at all. He claimed that he had the drug perfected, fixing all the defects and side effects. With Eddie's super intelligence, we can be rest assured that there was nothing impossible for him, including the creation of a more powerful "Smart Pill" that allows him to make an even more powerful "Smart Pill". Infinite intelligence? Maybe, like a "Big Bang" of intelligence. (I'm a strong believe in this happening one day, with or without drug.)

And why he wanted to be the president? Doing good? Got nothing better to do? Run the world the right way (my way)? Just hope that Eddie won't say to us what he said to his old boss, "you should be glad about me not working for you, because you'll end up as my bitch."