6. Season 2, Episode 10: “What They Become”
“What They Become” is one of the most important episodes of Agents of SHIELD. It centers on Coulson and his team rushing to destroy an ancient Kree island-city before Hydra can get to it and unlock a potentially extinction-level event. The episode is significant in that it introduces the Inhumans, a race of super-powered beings, in the extended MCU. In the comic books, the Inhumans are an alien race who live on the moon and are ruled by a royal family that includes heroes such as Blackbolt, Medusa, and Crystal.
In this version, Earth-bound humans who have an alien-like genetic predisposition have their powers activated when they are exposed to a mystical element called terrigen mists or crystals. While on a mission to obtain the alien Kree Obelisk from an ancient temple, Skye is trapped in a cave with the villainous Raina (Ruth Negga) and fellow agent Antoine “Trip” Triplett (B.J. Britt) when the mists are released into the atmosphere. The mist creates a cocoon-like material around all three of them, but Skye uses her newly awakened shockwave abilities to burst out of her own cocoon. Her new abilities shake the entire island, but she watches in horror as Trip’s petrified body crumbles before her.
We learn that Skye’s real name is Daisy Johnson, confirming that her character is indeed based on the Quake comic book character. Additionally, Skye’s father, Calvin Zabo, is based on the comic book villain Mr. Hyde. Terrigen mist is used to activate powers in dormant Inhumans, but is lethal to regular human beings. This episode is considered one of the most groundbreaking, changing the course of Agents of SHIELD, and the life of Daisy Johnson, forever.