The fight to survive has torn them apart, turned them against each other, and taken the lives of their closest friends. Last season, a new, even more dangerous threat arose: the A.I. that ended the world was building an army dedicated to controlling all sentient life on Earth. No longer a battle between warring factions; it was a fight for humanity itself. The 100 face their darkest chapter yet.

Wide screen. Based upon the book by Kass Morgan. Special features: All-new featurettes: From outcasts to leaders, Creating a post-apocalyptic world, The 100: Jasper's journey; Battle tested: the 100 season 4 stunts; The 100: 2016 Comic-con panel; gag reel; unaired scenes.

Disc 1. Episodes 1-5 -- disc 2. Episodes 6-10 -- disc 3. Episodes 11-13 ; Special features.