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Real Name: Terrence "Terry" Sorenson

Identity/Class: Human mutate

Occupation: Criminal, former temporary licensed super hero

Group Membership: None;
    formerly Freedom Force (Challenger/William Waring, Cloud 9, Spinner, Think Tank), 50-State Initiative, Vil-Anon (Big Wheel, Armadillo/Antonio Rodriguez, Hypno-Hustler/Antoine Delsoin, Man-Bull/William Taurens, Schizoid Man/Chip Martin)

Affiliations: Bloodshed (Wyndell Dichinson), Brother Grimm (Barton and Percival Grimes), Falcon (Sam Wilson), Force of Nature (Aqueduct, Skybreaker, Sunstreak, Terraformer), Ghost-Maker, Goldbug, Griffin, Grindhouse, Kogar, Alicia Masters, Mister Gryphon (Nathaniel Richards), Razor-Fist (Douglas Scott), Rogue (Anne Marie), Leonard Samson, Scorcher (Steven Jamal Hudak), Shadow Initiative (Badd Axe, Ringer, Warbow), Shadow Slasher (Xi-shan Hao), Shockwave (Lancaster Sneed), Vision

Enemies: Avengers (Captain America/Sam Wilson, Iron Man/Tony Stark, Ms. Marvel/Kamala Khan, Nova/Sam Alexander, Spider-Man/Miles Morales, Thor/Jane Foster), Avengers Resistance (Debrii, Gauntlet/Joseph Green, Justice/Vance Astrovik, Night Thrasher/Donyell Taylor, Rage, Scarlet Spider, Slapstick, Tigra, Ultragirl), Heavy Hitters (Nonstop, Prodigy, Telemetry), Heroes for Hire (Black Cat, Humbug, Misty Knight, Orka, Paladin, Shang-Chi, Tarantula, Colleen Wing), Human Torch (Johnny Storm), Iceman (Robert "Bobby" Drake), Skrulls, Spider-Man (Peter Parker), Vienna, Wasp, Yellowjacket

Known Relatives: Dr. Margay Sorenson (mother), Dr. David Sorenson (father, deceased), unidentified wife (deceased), Janet Sorenson (daughter)

Aliases: The Thermodynamic Man, "Noxie"

Base of Operations: A prison in Upstate New York;
    formerly the Raft, Ryker's Island;
    formerly Harlem and the rest of Manhattan, New York

First Appearance: (in shadows) Giant-Size Spider-Man#1 (July, 1974); (fully seen and identified) Marvel Team-Up I#23 (July, 1974)

Powers/Abilities: After originally gaining his power, Equinox's body was constantly in a state of thermodynamic flux, radiating waves of heat and cold at all times as coruscating sheets of fire and ice shifting over his entire frame. In this form, he could project flame, much like the Human Torch, or could project ice, much like Iceman, although his abilities were not as well honed as either of them. A side effect of his thermodynamic flux was immunity to heat/flame and cold/ice. Additionally, his body also possessed superhuman strength (Class 25, enabling him to lift/press approximately 25 tons) and durability, affording him a limited amount of protection from conventional physical- and energy-based damage.

Weaknesses: As noted above, Equinox originally radiated heat and cold at all times; he could not turn off his power. Later, he gained control over when his power manifested. He could only expel either heat or cold but not both, unless artificially aided (See Equipment). He also had a weakness to being caught in between phase shifts, and a blast of extreme cold could incapacitate him when he just began to turn to flames, or vice-versa. When his thermodynamic energy was unbalanced in such a manner, it erupted with explosive force. After his transformation, Equinox became extremely mentally unbalanced when his power was left unchecked and free.

Equipment: Equinox formerly wore a "protective shielding suit," which presumably regulated his temperature and his mental stability, in turn. Equinox was able to simultaneously project both fire and ice while in this suit, an ability he could not do naturally. Although the suit was somewhat durable, it did not afford Equinox any measure of protection from attacks.

Height: 6' 0"
Weight: 200 lbs.
Eyes: Brown
Hair: Bald


(Marvel Team-Up I#60 (fb)) - Terry Sorenson was the son of a pair of research scientists. His mother, Margay, rose to great success as an expert in the Natural Sciences, while his father, David, remained obscure in the field of Thermodynamics because his theories were too radical to be accepted. David Sorenson became increasingly frustrated and eventually began to physically take his anger out on his wife. In time, after a day spent in his lab with a bottle of bourbon, David was killed in an explosion of uncertain origin. Terry was close by his father's lab at the time of the explosion and was mutated into a being composed of both fire and ice.

Margay Sorenson took a leave of absence from teaching at Bard and tried to reconstruct David's notes in an effort to cure Terry but met with failure after failure. When money for equipment ran out, Terry began to steal what they needed. He became more bitter with each failure, as he progressively mutated, and the raging energies within him pushed him to the brink of insanity.

(Giant-Size Spider-Man#1) - Spider-Man discovered a burglar in Faversham Jewelers, but the shadowy figure fled from him. Spider-Man's web just slid off his form, and Spidey slipped on a sheet of ice--in 60 degree weather--enabling Equinox to escape.

Shortly thereafter, Spider-Man had to leave the area to locate medicine for his Aunt May, but he convinced Johnny Storm to look into the burglary for him.

(Marvel Team-Up I#23/Code of Honor#1 (endfight only) ) - As the Human Torch approached Faversham's, he was blasted out of the blue by an ice-bolt. Assuming that only the Iceman could have done this, the Torch tracked him down and attacked him, until learning he had an alibi. The Torch and Iceman then teamed up to investigate, and they headed back over to Faversham's, where they found Equinox completing his crime. Equinox proved able to stand up to their combined power, and his strength and version of their powers enabled him to fight them both off. They recovered, tracked him, and eventually managed to simultaneously nail him with an ice blast to his fiery upper half, and a flame blast to his icy loer half (watched by Lt. Piper, Michael Badalino and other cops). Equinox's energies suddenly climbed to critical mass and he seemingly exploded--he actually escaped into the sewer when he blasted out the road beneath him.

(Marvel Team-Up I#59-60) - Equinox ambushed Spider-Man as he was swinging over the Queensborough Bridge, knocking him out and sending him into the river. Yellowjacket saw this attack, rescued Spider-Man, and brought him back to his home, but Equinox followed him and attacked both of them, as well as the Wasp. Equinox stood against all three of them and managed to knock out the Wasp. Yellowjacket then attacked him solo and was seemingly killed when Equinox caused a powerful explosion. Spider-Man carried off the hysterical Wasp, and they joined together with Margay Sorenson, who had tracked her son's activities. Margay's energy stabilizer failed to stop Equinox, and they fled to the Baxter Building, where she might use Reed Richards' equipment to build a more powerful version. Equinox tracked them there, but together Spidey and Margay had built a better stabilizer. Spider-Man tried to subdue Equinox long enough to use the device, but Equinox overpowered, imprisoned, and beat him senseless. Suddenly, Yellowjacket returned and, aided by the Wasp's sting, placed the stabilizer on Equinox, neutralizing the thermodynamic changes going on in his body.

(Official Handbook of the Marvel Universe Deluxe Edition#10 - BTS) - Equinox was briefly imprisoned and studied at Project: PEGASUS. Presumably this is how his powers came under control.

(Spider-Man Unlimited II#12 (fb)) - At some point Equinox attended together with Armadillo, Man-Bull, Chip Martin and Jackson Weele a Vil-Anon (Villains Anonymous) meeting.

(Marvel Comics Presents I#147/3 (fb)OHotMU 2006/4 - BTS) - Terry Sorenson regained his sanity and gained control over his powers. He renounced crime and started a family, but his wife died and his daughter inherited his powers.

At the age of six, his daughter, Janet, began to demonstrate similar powers. Desperate to prevent her from going through the same problems he had, he tried to prevent her from using her powers. Janet could not control her abilities though and began to have intermittent outbursts, which--based on life's lessons learned from his own father--Terry tried to stifle with beatings.

(Marvel Comics Presents I#147/3) - Sam Wilson, the Falcon, investigated two seemingly unrelated subjects that turned out to have a common origin: (1) a series of explosions which had began to occur in Harlem, (2) the child abuse case of Janet Sorenson. Learning that Terry Sorenson had been Equinox, the Falcon showed up at his apartment in time to find him about to slap Janet. Wrongly assuming that Equinox was just a mean-spirited parent and an arsonist for hire, the Falcon flew into his room, which angered Terry enough to provoke him to use his powers against the Falcon. As the battle escalated between the Falcon and Equinox, Janet became increasingly distressed, until her powers caused another explosion.

Now knowing the truth, Sam Wilson helped prevent either Janet or Terry Sorenson from being taken into police custody. When Sam pointed out the similarities between Terry's treatment of Janet and his father's treatment of his mother, he saw things in a different light. Sam also gave Terry the number of some of his friends who could help Janet learn to control her powers.

(Heroes for Hire II#1) - Equinox attended a meeting with Vienna, who offered him and a few other costumed criminals new identities outside of the United States. Heroes for Hire attacked them, but Vienna expected them and the villains gained the upper hand on them with the aid of a few robots. Things changed when Paladin, Orka and Shang-Chi arrived and the villains were soon defeated. Afterwards it was revealed that Vienna worked together with the Heroes for Hire and that the operation was a test for HfH members Humbug and Tarantula.

(Civil War: Battle Damage Report#1) - Equinox was brought to the Negative Zone Prison Alpha and remained there despirte the prison break orchestrated by Captain America.

(Avengers: The Initiative#18 (fb) - BTS) - Equinox was captured by the Skrulls. The Skrull imposter joined the Initiative's Freedom Force team based in Montana.

(Avengers: The Initiative#18 - BTS) - The Equinox Skrull was exposed and killed.

(Secret Invasion#8 - BTS) - Equinox was freed when the ship with him and all the other replaced humans landed in Central Park.

(Avengers: The Initiative#20) - Equinox attended a meeting run by Alicia Masters (a former Skrull kidnap victim) and Leonard Samson, alongside the other former Skrull captives, meant to help them return to regular life.

(Astonishing Tales: The Thing#1) - Equinox met Thing at a sports bar and apologized for the fight at the Baxter Building years ago. He told Thing the origin of his powers and told him about his mother's death. Thing felt sorry and accepted the apology.

(Avengers: The Initiative#28) - When the Heavy Hitters (Nonstop, Prodigy, Telemetry) succeeded from the Initiative, Osborn sent the Force of Nature (Aqueduct, Skybreaker, Sunstreak, Terraformer), the U-Foes (Ironclad, Vapor, Vector, X-Ray), Freedom Force (Challenger, Cloud-9, Equinox, Think Tank), members of the Shadow Initiative (Badd Axe, Ringer (Keith Kraft), Warbow), and other trainees (Brother Grimm, Griffin, Scorcher, Razor-Fist) to attack them. They briefly battled the Avengers Resistance (Debrii, Gauntlet, Justice, Night Thrasher, Rage, Scarlet Spider, Slapstick, Tigra and Ultragirl). Prodigy and Night Thrasher were captured, but the others escaped.

(X-Men Legacy I#275 (fb)) - Equinox was transferred from the Raft to a prison in Upstate New York.

(X-Men Legacy I#275) - Still imprisoned Equinox, hoping he would get out earlier and be able to return to his daughter, volunteered to have a portion of his powers absorbed by X-Men member Rogue. His powers enabled her to thwart a prison break at the Upstate prison.

(Amazing Spider-Man I#682 (fb) - BTS) - Equinox started a protection racket in New York City and threatened to burn down buildings if he wasn't paid.

(Amazing Spider-Man I#682) - While burning down a building Equinox froze firefighters to the street, which caused one of the firefighters to lose a leg. Spider-Man defeated him quickly with grenades filled with thermoreactive foam, then cleared the way for an ambulance to give the firefighter a chance to get his foot reattached.


(All-New, All-Different Avengers#5 (fb) - BTS) - Equinox started serving Kang.

(All-New, All-Different Avengers#5) - Equinox and his time-displaced counterparts fought the Avengers (time-displaced by Mr. Gryphon aka. a version of Kang)

(All-New, All-Different Avengers#6) - More Equinox counterparts fought the Avengers and they were joined by Vision, who had been infected with a virus by Kang. Ultimately the Avengers defeated Equinox when Spider-Man (Morales) tricked the present-day Equinox to reveal himself and knocked him out (Spider-Man pretended to serve Kang as well and present-day Equinox stopped being a threat to Spider-Man's whose Spider-Sense wasn't activated by him anymore and this was how he knew it was him and this is smart, but I wrote it in the most convuluted way possible). With the present-day Equinox defeated all future versions disappeared.

(X-Men Unlimited III#20 - BTS) - At an unrevealed point in time, the Warden of superhuman prison the Dungeon acquired a genetic sample of Equinox which he later used amongst other samples to become the Human Adaptoid. While invading Krakoa, the Human Adaptoid activated Equinox's powers along with those of Arclight, Solarr, Vibro and others to combat Juggernaut and Deadpool.

Comments: Created by Len Wein, Ross Andru, and Gil Kane.

During the course of the struggle in Marvel Team Up#60, the fight dislodged the Soul Catcher Wand, which led to the release of the Super-Skrull a few issues later.

I placed the Spider-Man Unlimited flashback before the MCP appearance because Equinox was still trapped in his mutated form. Parallel to these meetings he probably got more help from Project: PEGASUS to regain his human form.
--Markus Raymond

In Marvel Team-Up I#59 an unfinished thought by Yellow Jacket (Pym) implied that Terry and his father had become Equinox. This could've been the original plan, but it ended up to be just Terry.
--Markus Raymond

Equinox has entries in All-New Official Handbook of the Marvel Universe A to Z#4 (April, 2006) and the Civil War: Battle Damage Report#1 (March, 2007).

Profile by Kyle Sims

Equinox has no known connections to

David Sorenson


Equinox's dad, he worked in Thermodynamics, but his theories were too radical to gain widespread acceptance. Jealous over his wife's success, he began to physically abuse her, as well as to sink into progressively deeper drinking binges. Finally, while working under the influence, he was killed by an explosion that also mutated his son Terry into Equinox.


--Marvel Team-Up I#59 (60 [fb], 59, 60)



Margay Sorenson


Equinox's mom, she was the head of Natural Sciences at Bard College and was quite renown for her work. She became a victim of her husband's jealousy over her success, and she lived with physical abuse for some time, in an effort to keep their family together for Terry. When Terry was transformed into Equinox, she took a leave of absence from her work to try to cure him. When she combined her efforts with Spider-Man, using the equipment of Reed Richards, she succeeded in bringing Equinox's powers back under control.

(Astonishing Tales: Thing#1 (fb) - BTS) - Soon after she died of breast cancer.


--Marvel Team-Up I#59 (60[fb], 59, 60, [Astonishing Tales: Thing#1 (fb)]


Janet Sorenson


The daughter of Equinox, she was a mutant (Marvel definition), whose powers surface around age six. Her dad tried to force her to contain her powers, but she couldn't and they were periodically causing explosions around their Harlem neighborhood. Equinox became frustrated with his inability to stop her outbursts, eventually to the point of violence. With the help of the Falcon, Equinox sought other non-violent means to control her powers.

She can release explosive bursts of energy.


--Marvel Comics Presents I#147/3





images: (without ads)
All-New Official Handbook of the Marvel Universe A to Z#4, Equinox entry (main image)
Marvel Team-Up I#59, p17, pan3 (triumphed)
Marvel Comics Presents I#147, p8, pan4 (human form)
X-Men Legacy I#275, p12, pan2 (cooperating with Rogue)
Marvel Team-Up I#60, p5, pan5 (David Sorenson)
Marvel Team-Up I#59, p9, pan4 (Margay Sorenson)
Marvel Comics Presents I#147, p4, pan3 (Janet Sorenson)

Giant-Size Spider-Man#1 (July, 1974) - Len Wein (writer), Ross Andru (pencils), Don Heck (inks), Roy Thomas (editor)
Marvel Team-Up I#23 (July, 1974) - Len Wein (writer), Gil Kane (pencils), Mike Esposito & David Hunt (inks), Roy Thomas (editor)
Marvel Team-Up I#59 (July, 1977) - Chris Claremont (writer), John Byrne (pencils), Dave Hunt (inks), Archie Goodwin (editor)
Marvel Team-Up I#60 (August, 1977) - Chris Claremont (writer), John Byrne (pencils), Dave Hunt (inks), Archie Goodwin (editor)
Offical Handbook of the Marvel Universe: Deluxe Edition#10 (September, 1986) - Mark Gruenwald, Peter Sanderson (writers), Josef Rubinstein (inks), Mark Gruenwald, Howard Mackie (editors)
Marvel Comics Presents I#147 (February, 1994) - Mariano Nicieza (writer), Steve Lieber (pencils/inks), Richard Ashford (editor)
Code of Honor#1 (January, 1997) - Chuck Dixon (writer), Brad Parker & Tristan Shane (artists), Kelly Corvese (editor)
Spider-Man Unlimited II#12 (January 2006) - by Christos Gage (writer), Mike McKone (penciler), Larry Stucker (inker), Tom Brevoort (editor)
All-New Official Handbook of the Marvel Universe A to Z#4 (April, 2006) - Jeff Christiansen, Sean McQuaid, Michael Hoskin, Eric J. Moreels, Mark O'English, Stuart Vandal, Ronald Byrd, Madison Carter, Mike Fichera, Anthony Flamini, Chris Biggs, Barry Reese, Henrique Ferreira (writers), Jeff Youngquist, Jennifer Grunwald (editors)
Heroes for Hire II#1 (October, 2006) - Justin Gray & Jimmy Palmiotti (writers), Billy Tucci (pencils), Tom Palmer (inks), Mark Paniccia (editor)
Civil War: Battle Damage Report#1 (March, 2007) - Ronald Byrd (writer), Anthony Flamini (head writer/coordinator), Michael Short (assistant editor), Jennifer Grunwald & Mark Beazley (editors, special projects), Jeff Youngquist (editor)
Avengers: The Initiative#18 (December, 2008) - Dan Slott, Christos Gage (writers), Steve Kurth (penciler), Drew Hennessey (inker), Tom Brevoort (editor)
Secret Invasion#8 (January, 2009) - Brian Michael Bendis (writer), Leinil Francis Yu (pencils), Mark Morales (inks), Tom Brevoort (editor)
Avengers: The Initiative#20 (February, 2009) - Dan Slott (writer), Steve Kurth (penciler), Drew Hennessy (inker), Tom Brevoort (editor)
Astonishing Tales: The Thing#1 (June, 2009) - Nelson DeCastro (writer/artist), Michael Horwitz (editor)
Avengers: The Initiative#28 (November, 2009) - Christos Gage (writer), Rafa Sandoval (penciler), Roger Bonet (inker), Bill Rosemann (editor)
X-Men Legacy I#275 (December, 2012) - Christos Gage (writer), David Baldeon (penciler), Jordi Tarragona (inker), Dan Ketchum (editor)
Amazing Spider-Man I#682 (May, 2012) - Dan Slott (writer), Stefano Caselli (artist), Stephen Wacker (editor)
All-New, All-Different Avengers#5 (April, 2016) - Mark Waid (writer), Mahmud Asrar (artist), Tom Brevoort & Will Moss (editors)
All-New, All-Different Avengers#6 (April, 2016) - Mark Waid (writer), Mahmud Asrar (artist), Tom Brevoort & Will Moss (editors)
X-Men Unlimited III#20 (January, 2022) - Fabian Nicieza (writer), Matt Horak (pencils, inks), Jordan D. White (editor)

First Posted: 04/05/2003
Last updated: 11/02/2023

Any Additions/Corrections? please let me know.

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