Premiere date: September 24, 2013
The story: Mysteriously resurrected after his death during The Avengers, Special Agent Phil Coulson assembles a small team of S.H.I.E.L.D. agents—including pilot Melinda May, black-ops agent Grant Ward, engineer Leo Fitz, and scientist Jemma Simmons—to battle Centipede, an organization that seeks to create Super Soldiers of its own. Coulson also recruits “Skye,” an orphaned hacker seeking to discover her parent’s identities, who learns the ropes as the group’s personalities grow into a team. Said trust is shattered, however, by the events of Captain America: The Winter Soldier, which reveal that several S.H.I.E.L.D. agents—including Ward—are Hydra plants, and that Coulson’s friend and fellow team leader, John Garrett, is the leader of Centipede (itself a covert Hydra cell). When Skye is shot on Garrett’s orders, Coulson saves her life with the same drug that resurrected him, learning in the process that it’s produced from the blood of an alien corpse (and that he himself was the leader of the project to harvest the serum, before having his memories wiped to maintain his sanity). Garrett—whose body is deteriorating from previous injuries—steals and uses the alien blood serum, driving himself insane in the process. He is ultimately taken down by Coulson, with help from Nick Fury and Centipede test subject Mike Peterson. Coulson is named the new director of S.H.I.E.L.D. by Fury, but soon begins exhibiting some of the same drug-based madness that afflicted Garrett before his death.
Season two: Coulson and his team begin waging war against Hydra leader Werner Reinhardt (a.k.a. Daniel Whitehall) for the Obelisk, a device originally found with the Kree alien body whose blood resuscitated Coulson. Mercenary Lance Hunter joins the team, hoping to avenge his former squadmates; meanwhile, Hunter’s ex-wife, S.H.I.E.L.D. agent Bobbi Morse, infiltrates Hydra, along with Simmons. Whitehall also works with Calvin Zabo, who’s revealed to be Skye’s father, and who tells her that her birth name is Daisy Johnson. The battle culminates in an alien city buried under San Juan, where the Obelisk opens, releasing the Terrigen Mists, which activate Johnson’s latent powers as an Inhuman but kill any normal humans who are exposed to them. Emerging from a cocoon, Johnson gains an uncontrollable ability to cause earthquakes; meanwhile, Coulson kills Whitehall.
Morse and the team’s mechanic, Mack, are revealed to be members of a faction referring to itself as “The Real S.H.I.E.L.D.” led by Robert Gonzales, which split off from the main organization during the initial Hydra attack, and which oppose Nick Fury and Coulson’s policy of extreme secrecy. The two factions wage a quiet civil war with each other, which is resolved when Coulson’s preparedness helps save the world during the events of Age Of Ultron. Meanwhile, Johnson is recruited by Jiaying, an Inhuman woman eventually revealed to be her mother, to join the secretive community of Afterlife. Jiaying is ultimately shown to be an anti-human warmonger, killing Gonzales to provoke a fight with S.H.I.E.L.D. and plotting to use the Terrigen Mists to wipe humanity off the planet. When Jiaying attempts to drain Johnson’s life force, Zabo turns on her, killing his former wife. Zabo then has his memories of his years as a villain erased, and is allowed to lead a normal life; meanwhile, Johnson is placed on a new S.H.I.E.L.D. team for “gifted” individuals, mutation-inducing crystals settle into the Earth’s atmosphere, and Simmons is pulled into a mysterious Kree artifact.
Season three: A three-way fight for control of Earth’s new Inhuman population—activated by the released crystals—breaks out between S.H.I.E.L.D.; its replacement organization, the Advanced Threat Containment Unit; and a monstrous Inhuman named Lash. Despite efforts by the ATCU to capture and create more Inhumans, Johnson recruits two more—metal-bender Joey Gutierrez and the electrically powered Lincoln Campbell—to her “Secret Warriors” team, under the guidance of Dr. Andrew Garner. Garner, who is also May’s ex-husband, is ultimately revealed to be Lash, driven by his Inhuman purpose to transform and kill “unworthy” Inhumans. Meanwhile, Fitz manages to rescue Simmons from the alien world she was exiled to, but learns that six months have passed from her point of view. Meanwhile, Hydra leader Gideon Malick, working with Ward, forces Fitz to reopen the portal so that they can bring a creature that lives there back to Earth, fulfilling Hydra’s ultimate purpose. Coulson follows Ward and Fitz through the portal, ultimately killing the former agent. However, Ward’s death unknowingly allows his body to be possessed by Hive, an ancient Inhuman that seeks to take over the world. Hive begins a process to change Earth’s entire population into Inhumans, who he can control via parasitic infection. Johnson falls under the ancient Inhuman’s sway, but is eventually rendered immune to the infection by Lash. Hive is ultimately defeated when Campbell sacrifices himself to blow both Hive and his viral warhead up in space.
Season four: It’s several months later, and the agents of S.H.I.E.L.D. are divided. A new director named Jeffrey Mace reintroduces S.H.I.E.L.D. to a wary public. However, it’s soon revealed the new director was given phony powers to create the illusion he’s an Inhuman. Once Coulson discovers the ruse, he retakes managing control of S.H.I.E.L.D., though Mace remains the public face. The team is eventually reunited while working with the mysterious Ghost Rider—an unkillable spirit of vengeance—to take down a scientist intent on unleashing the power of a mysterious book called the Darkhold. However, once the mad scientist is stopped, futurist Holden Radcliffe (introduced in season three helping Hive develop a virus that would have turned all of humanity into deformed primitives) uses the book’s knowledge to build Life Model Decoys—human-looking imitations of people uploaded with their consciousness. He starts to replace the members of S.H.I.E.L.D. with the aid of his robotic AI, Aida.
Daisy “Skye” Johnson
Alphonso “Mack” McKenzie
Noteworthy events: Phil Coulson is alive, thanks to the Kree’s introduction into the MCU. The release of the Terrigen Crystals gives a plausible excuse to add mutant-like superpowered characters to the universe on the cheap. And we get the first instances of a number of comic-book technologies, like quinjets and LMDs.