After an extended drug bender, addict Jake ventures out into the quiet streets to discover he's actually missed a terrifying global phenomenon.

Ellis' plan hits a snag, just in time for some sleepless delirium to settle in.

As Ellis heads for Dallas, Jake, Sam and Ally are diverted by a new kind of foe.

New clues converge in Dallas, while Ally attempts a dangerous reunion in Austin.

Lex shows her research to Ally; Ellis investigates a mysterious signal.

In the season finale, alliances at Dr. Abrams' facility are pushed to a breaking point; Ellis' group puts their theory to the test.