Quando o estudante de pós-graduação do MIT, Liam Cole, descobre que um asteróide está prestes a colidir com a Terra em 186 dias, une-se a um bilionário tecnológico, Darius Tanz, e ao governo dos EUA para tentar detê-lo.

Dario e Liam trabalham para inventar uma tecnologia teoricamente impossível para desviar o asteróide, e, Grace arrisca tudo para ajudar Darius. Para além disso, Liam dirige-se a Boston para localizar umas pesquisas críticas, mas encontra algo chocante.

É uma corrida contra o tempo e Darius deve acelerar o seu plano para parar o asteróide antes que o Pentágono acabe com ele. Grace tem de tomar decisões difíceis que podem ter consequências de vida ou morte para milhões de pessoas.

Para provar a Harris e Grace que ele não é um traidor, Darius deve revelar um segredo bem guardado. Liam ajuda Jillian a se adaptar ao seu novo emprego na Tanz.

Enquanto Darius trabalha para descobrir quem matou o seu amigo Lazlo, ele é forçado a contar com o seu passado. Liam descobre quem tem vendido segredos aos russos.

Darius recruta Grace, Harris e Liam para uma missão perigosa. Jillian confronta Liam sobre o seu segredo.

Grace and Darius slip off to Russia behind Harris’ back in an attempt to stop a potential nuclear conflict. Also, Liam seeks solace with Amanda.

Framed for murder, Darius and Grace must try to escape from Russia, and Liam tries to convince Jillian to come back to Tanz.

Grace narrowly escapes a deadly assassin and Darius and Liam forge unlikely alliances.

Grace and Darius seek answers from the President and Harris discovers deadly secrets.

Grace and Harris must forge an alliance when their children’s lives are in jeopardy. Also, Liam presents Jillian with an unusual proposal.

Darius, Grace and Harris join forces to prove the president was murdered. Also, Grace tells Zoe the truth.

Harris, Grace and Darius must topple the illegitimate government, and Darius makes final plans for the ark.

After a nuclear incident, the secret of the asteroid becomes public, setting the world on a dangerous course. Darius, Grace, Liam and Harris must adapt to new roles in an ever-shifting landscape of fear and civil unrest.

Darius and Grace must forge an emotional détente to get international cooperation. Liam meets a new scientist who has a mysterious past.

Grace is asked to lie under oath. Darius tasks Liam with a dangerous mission. A shocking act of violence plunges the nation into chaos.

Grace embarks on a dangerous mission, and Liam and Darius’ relationship is tested.

Grace forges a dangerous alliance with Claire’s brother, Alonzo. Also, Harris and Darius must work together to face down Bennett’s forces

Darius and Grace’s relationship is tested, and President Mackenzie attempts to bring the fractured country together while the hacktivist group ReSyst issues a deadly edict.

Darius vows revenge on the hacktivist group ReSyst, no matter what the cost. Also, Harris discovers a dark secret and Grace reveals one of her own.

Desperate to defuse a nuclear standoff, Liam receives help from an unlikely source. Also, with Darius missing, Harris and Grace take matters into their own hands.

Darius, Grace and Harris uncover the darkest secret yet, and Liam reconnects with Jillian.

Darius forms a dangerous alliance in order to destroy the dark money forces of Q17. Also, Grace takes action when surprising news jolts her world.

A stand-off at the COPE compound leads to tragic results

The government’s final plans for a doomsday scenario set in motion a surprising chain of events for Grace, Darius and Harris.

One last mystery holds the key to saving the world, and Grace must choose how she spends her final days.