" Ability ," the 14th episode of Fringe 's first season, is a pivotal turning point that shifts the series from a "monster-of-the-week" procedural into a high-stakes serialized mythology.

The plot centers on a horrific new threat: a toxin that causes human skin to grow at an accelerated rate, sealing victims' facial orifices and causing suffocation. Amidst this, the primary antagonist David Robert Jones resurfaces, surrendering to the FBI only to demand an audience with Agent Olivia Dunham. He presents her with a "test"—turning off a series of lights using only her mind—claiming she is a specially equipped soldier for an upcoming war.