Inside the hidden city of Attilan the silent leader Black Bolt insists on separation from the humans of Earth. But the king's brother, Maximus, leads a coup d'etat that will change the Inhumans forever.

In the wake of Maximus's coup the Royal Family is stranded on the island of Oahu, where Medusa tries to reunite with Black Bolt -- who quickly runs afoul of the Honolulu authorities. While Maximus tries to persuade Crystal, the ruthless enforcer Auran tracks the fugitives on Earth.

Maximus sends a team of powerful Inhumans to aid Auran in tracking down and eliminating the survivors of the royal family on Earth. Black Bolt is sent to county lock-up, and Karnak stumbles into a band of criminals. In Attilan, Maximus tries to convince Crystal to back him.

Black Bolt falls in with a genetic scientist, as Medusa joins forces with Louise in the hopes of tracking him down. Maximus makes a radical proposal to the Genetic Council, and Crystal must trust a stranger after Lockjaw is injured.

Karnak and a wounded Jen are forced to go on the run after Reno turns on them, while Crystal grows closer to Dave. Meanwhile Auran awakens in Declan's facility and determines to use him as leverage to draw out Black Bolt and Medusa. In Attilan, Maximus questions the loyalty of those closest to him.

With their family reunited Black Bolt and Medusa send Gorgon and Karnak to rescue Declan, while they take Louise in search of Crystal -- who plans to use her power over the elements to send them a signal. As the Inhumans clash with Auran's forces, on Attilan a faction plots to assassinate the false king Maximus.

The Royal Family returns to Attilan to retake the throne, but Medusa convinces Black Bolt to offer his brother a deal before the city devolves into civil war. Meanwhile Karnak turns to an unlikely ally in a desperate attempt to revive his cousin.

Maximus threatens to destroy all of Attilan, forcing the Royal Family to begin a massive evacuation of the Inhumans as Black Bolt faces off with his brother.