O conto é "Understand" de Ted Chiang. Da Wikipedia:
The story follows a man who is given an experimental drug to heal brain damage caused by anoxia after he nearly drowns. The drug regenerates his damaged neurons and has the unintended side effect of exponentially improving his intellect and motor skills. As he gets smarter and smarter, he is pursued by several government agencies and eventually receives a message from—and then enters into conflict with—another super-intelligent test subject.
Eu recomendo vivamente a coleção de contos de Chiang que contém esta história e outro trabalho brilhante, incluindo o conto que o filme de 2016 Chegada é baseado em.