The main Fear Itself miniseries, which debuted the following month, is written by Matt Fraction, and features illustrated interiors by Stuart Immonen and Wade von Grawbadger and covers by Steve McNiven.

The series, which depicts Captain America, the Avengers and others dealing with the aftermath of the events of "Fear Itself", is written by Fraction, Cullen Bunn and Chris Yost, and is illustrated by Mark Bagley and Paul Pelletier.

[40] The Mighty Thor #7 establishes the Serpent's origin story, revealing him to have been the sibling to Odin, Vili and Vi, who assumed the throne of Asgard following the death of their father, Bor, at the dawn of time, and whose rule was marked by madness and corruption.

[126] Danny Djeljosevic of Comics Bulletin saw Book of the Skull as Brubaker's embracing of the silliness of the Marvel Universe, and also questioned if readers would need the prologue to appreciate the crossover, saying that Captain America's presence in the story felt more like a marketing ploy than a natural aspect of it.

[133] At Newsarama, Jennifer Margret Smith praised Fraction's slow building of an uneasy fearful tone, his ability to play to smaller, less tangible emotions and for capturing the real-world parallels of the country's mood and Steve Rogers' Barack Obama-like characteristics in issue #1.

[136] George Marston felt the second issue built an air of paranoia and panic with an effective and utilitarian staccato pace, and enjoyed the surprising choices for the Worthy, saying that the series' main strength is relying on multiple ideas and story beats to create "a collective reading experience that may change the landscape of the Marvel Universe, [which doesn't do so] at the expense of its own readability.

The reviewers generally praised the writing and art, though Ray Tate, who expressed an aversion to large-scale "event" storylines, questioned the first issue's execution, and perceived out-of-character behavior on the part of Odin.

[143] Djeljosevic gave 4 bullets to issue #4, complimenting Fraction for hitting his stride as he scripted "the most technically daunting task in his comics career", and singling out the parallel scenes of Odin and the Serpent rallying their troops in particular.

[8][9][146][147][148][149][150] Alex Evans of Weekly Comic Book Review gave a "B+" to three of the first four issues, saying that Fraction effected a sincere, topically relevant and emotionally authentic story rather than a marketing ploy or editorial shuffle.

Evans felt the book utilized its scene-jumping structure to properly explore the expansive, global impact of the Worthy as a legitimate threat, and that both Bucky's death and Loki's humorous dialogue were well-handled.

[164][165][166][167][168] Rich Johnston of Bleeding Cool positively compared issue #623 to the 2011 Thor feature film, calling it the "perfect comic" for presenting Asgard in a "grandly poetic" light, "epic" and "beautiful".

[169] Reviewers at Comics Bulletin gave 4 out of 5 bullets to Journey Into Mystery #622, 624 and 625, giving Kieron Gillen high marks for his storytelling, characterization, humor and satisfyingly brisk pace, and Doug Braithwaite for his "wondrously detailed" art.

He compared it to the "Wiz Kids" segment of the 2001 Simpsons episode "Treehouse of Horror XII", and applauded its humor, emotion, the rendition of the different sides of Volstagg's personality, and the manner in which guest artist Rich Elson's refined, precise pencils addressed the previous problems Schedeen perceived in the series.

[7] Roman Colombo of Weekly Comic Book Review gave a "B+" to The Mighty Thor #7, saying that the prequel story of Odin and the Serpent's childhood did such a good job of providing a setup for the main storyline, and its impact so palpable that it should have been part of the prologue.

"[185] Ray Tate of Comics Bulletin gave 2 out of 5 bullets to Fear Itself: Youth in Revolt #1, attributing this to confusing plotting, implausible behavior on the part of bit characters and lack of independence from the core miniseries.

[73] Reviewing Fear Itself: The Black Widow, Kelly Thompson of Comic Book Resources criticized the in media res structure, saying that instead of the payoff demanded by such an approach, the result is an "eye-rolling deus ex machina-like cheat that in any movie-theater would illicit [sic] vocal groans."

[205] Jesse Schedeen of IGN gave the book a "Good" rating of 7 out of 10, describing it as a pointless tie-in with little effective conflict that does not fit well with the main storyline, albeit an enjoyable one with spy-flavored hijinks, and art that is fluid and energetic, if lacking in facial expressions.

Despite thinking that the citizens depicted were a bit too archetypal, he felt issue #1 properly covered the effects of the Serpent on the populace that were ignored by Fear Itself #2 that week, including those inflicted on Spider-Man that formed a classic set of insurmountable circumstances for him that rivaled his fight with Morlun in the 2005-2006 "The Other" storyline.

[207][208][209] Dean Stell of Weekly gave a "C" grade to the first two issues, saying that while it was not essential to the event, it established the street-level panic caused by it, providing "flavoring" to the crossover's story not present in the core miniseries, and that it featured many fine moments, his favorite of which was Spider-Man's confrontation with J. Jonah Jameson.

[210][211] James Hunt of Comic Book Resources praised issue #1 for "straddling the crossover line expertly", telling a genuine story rather than serving as an arbitrary tie-in, and for helping to allow the reader to understand the stakes of "Fear Itself" by showing the chaos created in the core miniseries.

Zawisza criticized Peter Milligan's Agents of Atlas story for lacking "pizzazz", a clear direction and consistent characterization, but found Elia Bonetti's art a nice transition between Mayhew's and Howard Chaykin's.

Stell also was unimpressed with Land's storytelling, his questionable choice in depicting Cyclops with beard stubble and putting Emma Frost in a cowgirl outfit for no discernible reason, and with Justin Ponsor's color palette and overabundance of highlights.

Although he loved the thrashing that Colossus gave Juggernaut after decades of stories in which the latter dispatched the former, he disliked the Namor-Emma Frost romance, the Kitty-Peter drama, and Cyclops' haughty demeanor toward the Mayor of San Francisco.

However, Hunt felt the story suffered from being almost unrelated to the core "Fear Itself" storyline, and criticized the lack of clarity over the identity of the "unknown superhero" in danger, stating that it failed to invest the reader in his fate.

[223] Jesse Schedeen of IGN, however, gave each of the three issues "Mediocre" ratings of 5.5, 5.0 and 5.5 out of 10, complaining that the story was barely related to the crossover, that the characterization was "bland" and unengaging, the humor "stilted", that it was entertaining on only a superficial level, and of Simone Bianchi's poorly defined and figure-crowded page construction, bizarre anatomy and storytelling that lacked a proper flow.

[227] Poet Mase of IGN gave issue #1 an "Okay" rating of 6.5 out of 10, saying that while he felt the villain's plot was plausible, it was somewhat stifled under the weight of text exposition that should have been handled by the visuals, and was unimpressed by Boschi's art or Dan Brown's colors, with some frames looking unfinished.

[75][76][77][78][231] Jamil Scalese of Comics Bulletin gave 4 out of 5 bullets to issue #160, also cheered Parker's crossover tie-in abilities, recalling his Thunderbolts work during the 2010 "Shadowland" storyline, and commending Declan Shalvey's rendition of the characters as "superb", and the style he employed when depicting the heroes infiltrating Juggernaut's soul.

[238] Doug Zawisza found Fear Itself: Fearsome Four #1's attempt to marry the disparate art styles of Michael Kaluta, Ryan Bodenheim, and Simon Bisley uneven and inconsistent (in particular their different renderings of Howard the Duck), even though each artist served their purpose, with the end result reading like "a poor man’s anthology that’s written to fill a projected collected edition than a coherent run at a single tale."

[240][241] Jesse Schedeen of IGN gave issue #1 a "Mediocre" rating of 5.5, saying that despite the clever premise, citing a lack of emotional appeal or any narrative rationale in the choice of the book's cast, the inconsistent tone, and an artist roster that creates a "jumbled" feel.

"[245] Dean Stell of Weekly Comic Book Review gave the issue a "B" for recapturing the feel of the 1980s series, and describing it as "mostly a big, fast-paced fight scene that works really well and is enjoyable to read", though he was disinterested by the political aspects of the plot, and disliked the use of Northstar.