4x13 "Praimfaya"

Sinopsis:
SEASON FINALE - It's a race against the end of the world as Praimfaya arrives forcing our heroes to make impossible decisions to ensure their survival. Eliza Taylor, Bob Morley, Paige Turco, Marie Avgeropoulos, Devon Bostick, Lindsey Morgan, Christopher Larkin, Richard Harmon, Zach McGowan, Isaiah Washington and Henry Ian Cusick star. Dean White directed the episode written by Jason Rothenberg (#413). Original airdate 5/24/2017.