As the survivors prepare to escape the area by raft, Alicia turns back to save one more person trapped in the fallout.

After going undercover at PADRE, Morgan and Madison find themselves back at odds trying to do what's best for Mo while struggling to accept their new lives under the watchful eye of PADRE.

The group searches for a new home; concerned for Grace, Morgan makes a tough call.

When Charlie shows up at the Tower unexpectedly, Howard recruits a young Ranger in training to determine the reason for her visit; as they journey beyond the Tower together, Charlie's true motives are revealed.

A survivor is at odds with the rest of the island and is forced to turn to another for help.

The horde led by Troy surrounds the walls of PADRE. Madison and her people must fight for their survival to save what remains.

Alicia takes refuge in the home of a mysterious stranger. With her fevers growing worse and Arno pursuing her at every turn, Alicia is forced to confront the failings of her past and how she will face her future.

The group, traveling in a convoy, doubles-down on their mission to find and help survivors.

As Morgan, Grace and Mo struggle to adapt to life on the submarine, a food shortage forces them to face the nuclear fallout outside the sub.

The heroes fight the clock and PADRE's forces.

Grace wakes up with her memory blurred and sees what her world's become years later.

Morgan searches for Al, only to discover that he's not the only one looking for her, and that his search may have put a target on his own back.

Mo's hunt to prove PADRE's true intentions has her in over her head as she's drawn into the larger web of secrets and subterfuge of the adults who care for her.

Dwight and Sherry confront the demons of their past to secure a better future for themselves.

As the series comes to an end, the fate of PADRE's survivors seems to rest in the hands of an unexpected hero.

As the battle for the Tower heats up, Alicia brings the fight to Strand's front door.

Morgan and Alicia plan their next steps; Dwight and Sherry face the prospect of having to choose between their code and their safety.

Morgan fights his past as he and Madison race to stop PADRE's expansion.

Alicia and Strand answer a call for help; Morgan and Al hit a roadblock.

Luciana and Wes test the limits of their patience when Daniel’s worsening mental state ends up endangering them all.

When baby Mo goes missing inside the Tower, Dorie Sr. finds himself in a unique position to prove his worth to an increasingly paranoid Strand.

Strand fights to maintain the peace of his new life after the sudden arrival of an old friend threatens it with ghosts of the past.

Facing an unknown future, Morgan leads the group on a mission; John and June make a promise.

Morgan finds a new ally who turns out to be more trouble than he bargained for.

Morgan struggles to find the strength to help friends in dire need before it's too late.