Alan Glynn 
Limitless 

Imagine a drug that made your brain function with perfect efficiency, tapping into your deepest resources of creativity, intelligence and drive. A drug that can help you learn a foreign language in a day. A drug that can help you process information so fast you can see patterns in the stock market. Just as his life is fading into mediocrity, Eddie Spinola discovers such a pill: MDT-48, Viagra for the brain. But while the benefits of such a mind-drug quickly start to materialise, so too do the side-effects. And when Eddie tries to track down other users, to help him kick his addiction, he finds out that they're all dying, or dead…