Day Zero

Blake Edwards' hand is forced when the other survivors stop tolerating his drug habit. Frustrated by the inability to comprehend the situation, Blake engages in taking on the radiation-infected hybrids alone.

Blake's newfound path from destruction becomes a tedious work in progress. Meanwhile, Rachael and Cameron commit a mistake that needlessly places all of the survivors' lives in jeopardy.

Landon Parker must learn to deal with the others' patronizing ways surrounding his deafness. And the survivors soon discover they aren't exactly alone.

The survivors face a loyalty issue with the new visitors. Later, Russell Braddock's heroic plans backfire

Russell reflects on how he met Kat Finch sometime after Day Zero.

Jim Lecter's delusions take him to places he'd rather soon forget.

An embarrassing moment arises as Russell's thoughts are misinterpreted, leading to rumors.

A plan to leave the camp after a hybrid incident, is met with mixed emotions. Soon, a revelation is brought to light regarding the hybrids as Rachael becomes a liability.

Cameron's altered behavior creates fear among the group. Elsewhere, Blake and Rachael have an intimate discussion.

The season ends with an increased hybrid presence, threatening the survivors' hopes of keeping their home base. And efforts to find a cure to save one of their own, forces them to contemplate mercy killing.