The series sees S.H.I.E.L.D. Agent Phil Coulson putting together a small team of S.H.I.E.L.D. agents to handle strange new cases. In the first season, Coulson and his team investigate Project Centipede and their leader, the "Clairvoyant", eventually uncovering that Project Centipede is backed by Hydra and must deal with Hydra's infiltration, and the destruction of S.H.I.E.L.D. In the second season, Coulson and his team look to restore trust from the government and public following S.H.I.E.L.D.'s collapse.
Headlining the series, Agent Coulson oversees many of S.H.I.E.L.D.'s field operations, having been revived by medical technicians after his apparent death at the hands of Loki. Speaking of his character's return from the dead, Gregg said, "...the mystery and the complexity and the unanswered questions about Phil Coulson standing there trying to deal with this, I found it so fascinating and so true to the world of the comics and mythology in general as I understand them that I was immediately in." The changes to Coulson since his near death experience are explored during the first season. Executive producer Jeffrey Bell explains, "There is a lot that's strange and different about Coulson since his return to duty, and even he's noticing it. It sets him on a quest. "What happened to me? Why am I feeling this way? Who am I?" Executive producer Jeph Loeb adds that Coulson may regret uncovering his answers saying "When you start to pull on a thread, you run the risk of unraveling the whole sweater". Coulson's revival is revealed to have taken place much later than first implied, a matter of days not minutes, and with the assistance of a serum of alien origin. By the end of the first season he is appointed the new Director of S.H.I.E.L.D. by Fury and tasked with rebuilding the agency.
A S.H.I.E.L.D. ace pilot and weapons expert, whose nickname is "the Cavalry", although she dislikes the name, as the events that led to its coining during her time as a field agent haunt her, having left her "very quiet and a little damaged". The experience was so horrific that she took an obscure desk job before Coulson recruits her in the series pilot. According to Wen, May "needed to be saved. She returned to S.H.I.E.L.D. out of loyalty to Coulson, but there's a part of her that remains reluctant. If it weren't for his intervention, she'd still be down in that dark, dingy room stapling things." The character was originally listed with the name Agent Althea Rice on casting sheets. In the episode "Yes Men", she is revealed to be aware of how Coulson was resurrected, and to be spying on Coulson on behalf of Nick Fury, as revealed in "Turn, Turn, Turn".
A S.H.I.E.L.D. black ops specialist. He is a gruff, unsociable "manly man" in his early 30s who is great at his job, but not so great at getting along with his coworkers. Ward appeared to have strong moral foundation and is not without his charm. After a traumatic encounter in the episode "The Well", he begins a sexual affair with Agent May. The affair ends in the episode "Yes Men". Ward is revealed to be a Hydra agent in "Turn, Turn, Turn". In the season finale "Beginning of the End", May defeats Ward in a fight and he is arrested by the U.S. military.
A civilian computer hacker and member of the hacktivist group called "the Rising Tide", with an obsession for superheroes, whom Coulson recruits in the pilot episode. Skye is described as "bubbly and goofy" but "also warm, edgy and witty". She can more than hold her own in any situation. In "The Girl with the Flower Dress", it is revealed that Skye joined S.H.I.E.L.D. and Rising Tide in order to find out about her parents. In "Seeds", it is revealed that Skye was designated by S.H.I.E.L.D. as an "0-8-4" (object of unknown origin). After she is shot twice in the stomach and given hours to live in the episode "T.R.A.C.K.S.", she is subjected to the same regenerative serum used to revive Coulson, in "T.A.H.I.T.I." In "Yes Men", Coulson shares the secret alien nature of the serum with her, and the two make a pact to work together to uncover more information about it. She becomes a S.H.I.E.L.D. agent in the episode "End of the Beginning" with level 1 clearance, although the agency is then dismantled in the following episode, "Turn, Turn, Turn".
An agent of S.H.I.E.L.D. who specializes in engineering, especially weapons technology. De Caestacker downplays the apparent romantic chemistry between Fitz and Simmons, insisting that Simmons is merely "motherly" toward Fitz. Described as "superorganized", the character keeps only bare essentials on his worktable, with the exception of a monkey figurine that is a nod to De Caestecker's obsession with monkeys. In the season finale "Beginning of the End", Fitz confesses to Simmons that he has romantic feelings towards her. Fitz nearly dies helping Simmons escape from a submerged container in "Beginning of the End", and his fate is unknown, though he is confirmed to be alive.
In July 2012, Marvel Television entered into discussions with ABC to do a new show set in the Marvel Cinematic Universe, though at that point it was undecided what the show would be. It was described as "'a kernel of an idea' with a number of scenarios being explored, including a high-concept cop show." In August 2012, it was announced that Marvel's The Avengers director Joss Whedon, creator of cult hit shows such as Buffy the Vampire Slayer and Firefly, would be involved in the show's development. A few weeks later ABC ordered a pilot for a show called S.H.I.E.L.D. to be written and directed by Joss Whedon, with Jed Whedon and Maurissa Tancharoen also writing. Jed Whedon, Tancharoen and Jeffrey Bell would act as the series' showrunners. Disney CEO Bob Iger greenlit the S.H.I.E.L.D. series after watching the Marvel One-Shot short film Item 47, about S.H.I.E.L.D. agents pursuing a couple in possession of a Chitauri weapon used in the Battle of New York in The Avengers.
In April 2013, ABC announced that the show would be titled Marvel's Agents of S.H.I.E.L.D. and eventually officially picked up the series for a full season. In July 2013, Jed Whedon said the series will work in tandem with the Marvel films, both past and upcoming, saying, “We plan on trying to weave in between the films and try to make them more rewarding on both ends.” Also In July, Maurissa Tancharoen revealed on her Twitter page that Joss Whedon, Jed Whedon, Jeff Bell, Paul Zbyszewski, Monica Owusu-Breen, Brent Fletcher, Lauren LeFranc, Rafe Judkins and Shalisha Francis would be the writers for the series. Additionally, composer Bear McCreary confirmed that he would compose music for the series. In March 2014, the producers stated at the show's PaleyFest panel that they and the writers are able to read the screenplays for upcoming MCU films to know where the universe is heading, which allowed them to form a general plan for the show through the end of a third season, should the show be renewed for such.
The main recurring setting for the series is the Bus, a retrofitted Boeing C-17, that serves as both the transportation and headquarters of the titular team. The Bus includes such features as a soundproof interrogation room, a forensics and research lab located on the lower deck, where Fitz and Simmons work, and a cargo hold directly outside the lab where the team parks its SUV and Lola, Coulson's prized Chevy Corvette. Filming for the series takes place in Culver City, California, while the main visual effects for the series are done by FuseFX, with additional help from CoSA VFX. Additionally, Industrial Light & Magic shares assets from the films to ensure consistency across the properties.
The series' first tie-in episode with the Marvel Cinematic Universe is in the episode "The Well", which takes place after the events of the 2013 film Thor: The Dark World. A second tie-in takes place revolving around the events of Captain America: The Winter Soldier, in the episodes "End of the Beginning" and "Turn, Turn, Turn", which eventually lead to a retooling of the show for the final episodes of season 1. Beginning with "T.A.H.I.T.I.", all episodes leading up to The Winter Soldier crossover were part of a series of episodes dubbed "Uprising". For the second season, Tancharoen stated the production team was not ruling out creating crossover episodes with Agent Carter or Guardians of the Galaxy, with Whedon adding that any such episodes would not equal the scale seen in the The Winter Soldier crossover, saying, "In terms of game-changers, [those episodes are] hard to beat."
The series has been licensed in 155 countries and territories. It originally premiered on September 24, 2013. CTV announced in June 2013 that they hold the broadcast rights for Canada, and the series debuted alongside the American broadcast. On August 22, 2013, it was confirmed that Channel 4 would air the show in the United Kingdom, and it premiered on September 27, 2013. In Australia, the show premiered on Channel 7 on October 2, 2013, with the broadcast of the first two episodes.
The complete first season was released on September 9, 2014, on Blu-ray and DVD. Bonus features include behind-the-scenes featurettes, audio commentary, deleted scenes, a blooper reel, as well as the television special, Marvel Studios: Assembling a Universe.
In the United States, the premiere episode of Agents of S.H.I.E.L.D. earned a 4.7/14 rating in the 18–49 year old demographic, with 12.12 million total viewers, making it the biggest network drama debut in four years. Though the series debuted to strong ratings against its competition, NCIS, its ratings declined considerably over the following two months, though it remained Tuesday's top show among men 18–49, and overall was the No. 3 show among upscale young adults behind Modern Family and The Big Bang Theory. It also enjoys DVR recordings that, according to TV Guide, are "through the roof".
In Canada, the first episode on CTV, which premiered with the United States, saw 2.706 million viewers, earning the third highest viewership for the week on the network. In the United Kingdom, the debut episode three days later on Channel 4 saw the biggest drama launch of the year, averaging 3.23 million viewers including the +1 channel and recordings viewed the same night, or a share of 14.8 percent of people watching TV in the UK at the time. The Seven Network premiere in Australia on October 2, 2013 was watched by 1.3 million viewers, the top show of the night. In New Zealand, the first episode premiered on February 16, 2014 to 326,790 viewers, the fourth highest show of the night, and the most watched show on TV2.
Before the premiere, the entire pilot was screened at San Diego Comic-Con International in July 2013, and was met with a very positive reaction from the crowd. Critically, the initial screening of the pilot was met with mostly positive reviews. As of September 28, 2013, based on the pilot, the first season has received positive reviews from some critics, and received a Metacritic score of 74 out of 100, based on 32 reviews.IGN gave the pilot an 8.5 out of 10, saying it "quickly hits the right notes to firmly show how it exists on the ground level" of the Marvel Cinematic Universe.The New York Times' Brooks Barnes felt the storyline in the pilot was hard to follow at times, and did not like the thick accents of De Caestecker and Henstridge. He also added that "what goes over well at Comic-Con does not necessarily work in the real world," especially on a network with "Scandal moms and Dancing with the Stars grandparents".
Entertainment Weekly's initial reactions were that if everything that made the show appealing—its continuity with Marvel Cinematic Universe, its continuance of the The Avengers storyline, and Whedon's return to television—were stripped from it, the show would still work. However, they also questioned whether the show was accessible enough to attract a wider audience.Variety's Brian Lowry felt that the "pilot picks up where 'Avengers' left off, but doesn't pack quite the same punch," adding that the banter "occasionally feels a little precious and clunky."
Jim Steranko, an artist and writer who worked on 18 of the Nick Fury: Agent of S.H.I.E.L.D. comic books between 1966 and 1968, was critical of the pilot episode, lamenting that "the show had no menace, no tension." For the second episode, Steranko said that it was "too unfocused to be satisfying," but praised Jackson's cameo as Nick Fury as "an electrifying reminder of what the series could and should be." In contrast, Steranko's opinion of some later episodes in the first season were more positive, congratulating the writer and director of "The End of the Beginning" for "finding an entertaining, bravura groove that finally brings the concept to life", and saying of the next episode "I was concerned that last week’s bravura transformation was only a fluke, but it was apparent from the opening moments that the exec lineup’s new image-and-edit policy was in play." Overall, however, he found season 1 to be "22 episodes of 'sanctified' plot and character crumbs being salted with terminally-sluggish velocity (into anemic 'standalone' stories)".
In July 2014, Marvel Custom Solutions and Lexus announced a custom comic, Marvel's Agents of S.H.I.E.L.D.: The Chase #1. The comic shows a never before seen mission, taking place after the season 1 episode, "Seeds". Jonathan Rheingold, Vice President of Marvel Custom Solutions said, "Lexus, Marvel and the team behind Marvel’s Agents S.H.I.E.L.D. collaborated to create a backstory to the TV series that has utter continuity with the show, and offer existing fans exclusive content".
Also in July 2014 at San Diego Comic-Con International, Marvel Comics announced the ongoing series titled S.H.I.E.L.D., which will be set in the mainstream Marvel Universe (also known as Earth-616). The series will be written by Mark Waid and art by a rotating group of artists including Carlos Pacheco, Alan Davis and Chris Sprouse beginning December 2014. The series is led by Agent Coulson, and will see the canonical introduction of characters that originated from the television series, to which Waid said, "This is our chance to introduce a lot of the other characters into the Marvel Universe, and give them the Marvel Universe spin." Waid described the series as "done-in-one. Coulson and his team have a mission, and if we need someone for a mission, everyone in the Marvel Universe is available as a potential Agent."