According to a special thanks at the top of the splash page, Fusion was created by "the fans at Maplecon II in Ottawa". But Denny O'Neil must have liked the idea of combining two characters into one. He did it again nine issues later with the Mud-Monster.
There is a traffic accident and pile-up on the Fifty-Ninth Street bridge into Queens and it will "stall cars all the way across Manhattan". Spidey is due at the Daily Globe (yes, another story of Spidey at the Globe. I don't have to explain this again, do I?) but he figures that helping out will be good for his public image. On the bridge, the two men involved in the accident are busy insulting each other. Spidey leaps down and cheerily moves both dented cars out of the way so traffic can go through. But the car owners are not at all pleased. "Dummy!", cries one, "Don't touch it!" It seems that the cops have not yet arrived to make out a report. With the cars now moved, "we'll never collect the insurance now." "Stupid creep", yells one man at Spidey. "G'wan... get lost!", yells the other. A chastised Spidey decides he should "leave good deeds to the Boy Scouts". "Probably a commie", mutters someone as the webhead departs.
At an "Experimental Physics Laboratory" in a suburb of Newark, Dr. Hubert Fusser, the research director, revels in the completion of his "sub-atomic particle accelerator". Hubert is a middle-aged man in a lab coat who smokes a pipe and wears half-lens reading glasses. He also happens to be a midget. And a twin. Dr. Fusser knows that his machine should be "safety-checked" but he is so anxious to "plumb the deepest secrets of the universe" that he convinces himself that "nothing can go wrong". His confidence is questioned by his identical twin, Pinky Fusser, who wears a green maintenance shirt and arrives carrying a mop and bucket. For, while Hubert became a respected scientist, his brother became a janitor for the same organization. (Hey, it could happen!) Pinky warns his brother of possible mishaps but Hubert replies by reminding his twin of his "lowly" status. Bragging that he did not reach his present position by being careless, and that he designed everything in the lab, Hubert enters the room that houses his machine. He flips a switch and (of course) things go immediately wrong. "Raw energy" streams out of the machine and engulfs him. Pinky, watching from outside, sees his brother collapse and he bravely enters the room, trying to rescue Hubert. He ignores the blinding light and the pain, "like my skin's on fire" and reaches down to pull his brother out. But instead, "their flesh seems to melt... to merge... and become one".
At the Daily Globe, Peter Parker is late for "the most important editorial meeting of the year" because he stopped to help out on the bridge. A secretary tells him that everyone is waiting for him... "including Mister Dockery". When Pete asks who Mr. Dockery is, the cryptic reply is, "You'll find out." Entering the office, Peter receives a tongue-lashing from April Maye, the number one reporter for the Globe, who tells him to "sit down and shut up!" At the head of the table, Globe Editor Barney Bushkin introduces the "new Circulation Manager--direct from the Los Angeles Courier--Mister Rupert Dockery". Dockery stands and gives a small speech about the Daily Globe being "overly concerned with printing facts". When Peter challenges this statement ("Isn't that what a newspaper's for?"), Barney formally introduces the two men. The trouble is, Barney introduces Peter as "one of our chief shutterbugs". Since Pete thought he was the only chief photographer, he wonders who the other one is.
He doesn't have long to wait to find out. Right after the meeting, Barney takes him to meet Lance Bannon. He tells the two photogs that they will share office space. Neither one seems particularly happy to meet the other.
Later, Spidey swings through the city feeling sorry for himself ("Dockery's smarmy, Bannon's snotty.. and he's ruining my privacy to boot"). He has promised to meet his Aunt May at the hospital so the two of them can visit Anna Watson, who is having gall bladder trouble. When Pete and May enter Anna's room, they are told that Mary Jane has just left. Pete's not heartbroken that he missed her. After all, MJ turned him down when he asked her to marry him. But, in the midst of the visit, his spider-sense starts jangling, so he makes his excuse to the two women and runs down the hallway. It's not hard to tell from where the trouble emanates. Everyone else is running the other way.
Feeling "corny" about changing clothes in a broom closet, Pete emerges as Spider-Man and runs along the ceiling to escape the crunch of fleeing people below. He soon comes upon a small glowing creature, unclothed, looking like molten gold, with no facial features except a pair of white pupil-less eyes. It stands over an unconscious nurse. "If that's human, I'm a Martian", Spidey thinks. He decides to use his webbing to pull the nurse away from the monster. As he does so, he tries to "open a meaningful dialogue", but the glowing creature dives out the window instead. Spidey is stunned by this because they are up on the sixth floor!
He looks out the window, expecting a "glowing smear on the sidewalk", but instead discovers that the fall did not faze the creature at all; that, in fact, the glowing being looks "bigger... stronger". Spidey decides that a "walking heap of silly putty" should probably not be wandering loose in the city. He swings down in pursuit.
In Anna Watson's hospital room, May Parker watches the proceedings from the window. She tells Anna that Spider-Man is after some monster, then goes on to say that Spidey is not as bad as people think. "Why, he saved my life once!", she says. (At this stage, May is probably referring to ASM #200 but it could be any number of other times. Too bad she didn't maintain this lenient view of the wall-crawler. Too bad her more lenient character was changed into some DNA-construct imposter.)
Spidey gets down to the street and asks the monster to identify itself. This time it speaks... and calls itself Fusion. In confronting Fusion, Spidey barely touches him and is repelled back so far that he lands on a nearby roof. ("The comic book guy with the cape never has these problems.") Fusion, meanwhile, staggers away through Manhattan traffic. Whatever he touches loses power. Vehicles stall and traffic lights go out. Finally, Fusion pauses and decides, with one voice, that he "must go home". But another voice, also coming from Fusion, responds, "no". The voice that seeks home takes control of the body and descends into the subway. The other voice argues that they "have a great opportunity" but the first voice isn't listening. He wants to break free of his brother. And down by the turnstiles, Fusion splits in two and becomes, once again, Hubert and Pinky Fusser.
The two brothers sprawl on the ground, trying to recover. Pinky, the one who wants to go home, tells Hubert that what has happened to them is "carryin' brotherhood too dang far", but Hubert replies that they "have become the greatest phenomenon in the history of science"... a being that can absorb "energy from whatever we made contact with, from the fall, the cars". Pinky is uninterested. "You'll have to absorb energy without me", he tells his brother, "I'm cuttin' out." But, as Pinky leaves, he suddenly grows faint and collapses. Hubert passes out at the same time, only to topple off the platform onto the subway tracks. (Hey, when did they even go through the turnstiles?) Both recover but Hubert is too weak to move... and a train bares down on him. In desperation, Pinky crawls to the yellow line and over, joining his brother on the tracks. As the two men meet, they become Fusion once again. When the train hits, it immediately stalls out and Fusion absorbs the "momentum and impact of the train" into his body. With Hubert now in ascendance, Fusion places his left foot on the third rail and absorbs a million volts of power. But a thin voice replies from within, "it ain't right, Hube". Hubert doesn't listen. As Fusion walks along the tracks, the intoxicated scientist decides, "We must test our potential."
Back at the hospital, a recovered Spidey can't figure out where his opponent has gone. With no leads to follow, he decides to re-don his Peter Parker duds and return to Anna Watson's room. His excuse for his absence is that he "met a nurse I know". May is pleased. "My Peter's getting interested in girls, Anna.", she says. (Does she mean "interested in girls" again since being dumped by MJ or is May just seriously out of it?) Anna announces that it is time for her nap so her visitors depart.
Peter returns May to the nursing home at which she lives at this point in the Spider-history and goes out in search of Fusion. He comes upon a police car speeding through traffic with sirens wailing and wonders if they are after the same thing he is. He lands on the roof of the car, leans over, and knocks on the windshield. Fortunately, this maneuver does not cause an accident (though the driver is so traumatized, he has to tell himself, "I'm not going to look, I'm just going to drive"). Spidey has a chat with the cop riding shotgun who tells him that they are "heading for the Upper West Side. The entire area's blacked out." Spidey decides this can't be a coincidence. He heads for the Upper West Side.
Soon, Spidey arrives at the George Washington Bridge. (Whoa! Hold it, Spidey! What about the Upper West Side? You passed it!) He finds a traffic jam on the bridge that "makes the one I saw this morning look like the Indianapolis 500". All the cars are stalled out. Even their headlights are out. (OK, I admit it. I thought it was the middle of the day, too. Just roll with it.) Following the trail of dead automobiles, Spidey finally arrives at the source. "The walking power shortage", Fusion, traversing the bridge, touching cars as he goes. ("We have assimilated millions of units of energy and we are hungry for more", says Hubert. "Not we, Hube... you.", replies Pinky.)
Spidey engages Fusion by leaping off the hood of a car and spraying the glowing being with webbing. But Fusion scoffs at this. He absorbs "the energy of the chemical reaction in your web fluid as easily as I absorb electricity" and steps right through the webbing. Spidey steps in front of him. He has realized where Fusion must be heading and he knows he must stop him. (Oh, wait. I just remembered. Wasn't Fusion created in a lab in New Jersey? What'd he do, take a sightseeing detour through Manhattan? Now I'm completely turned around.) Spidey takes a punch at the three-foot terror and, just like before, is repelled away. But he can't give up. He knows Fusion is heading for the Indian Point Nuclear Power Plant and he must stop him from absorbing all that energy. Coming up behind Fusion, he wraps him in a bear hug. But, this doesn't work either. Spidey is repelled far away again. The people on the bridge, standing around their stalled autos, all seem to think this is pretty funny.
Spidey gets up and pursues. As Fusion mutters to himself (Pinky and Hubert arguing again), Spidey gets an idea. He pulls a steel bridge cable loose and fashions it into a lasso. He swings down and wraps it around Fusion. This time, Fusion can't shock himself loose and he can't affect the ungrounded web-slinger. Deciding that contact with water will shock Fusion, Spidey tosses his opponent into the Hudson. But it doesn't work. Fusion gets loose of the lasso. Then, "by stamping hard on the water's surface", he creates a nuclear reaction that allows him to walk on the water. ("Another validation of my theories", says Hubert. "Nother validation of your craziness", Pinky replies.)
Fusion arrives on the Jersey shore where Spidey soon reaches him. The wall-crawler has figured out that Fusion is composed of two individuals and the creature doesn't bother to deny it. Fusion tells Spidey to get out of the way. The webhead doesn't know how to stop Fusion but he knows he can't allow him to reach the nuclear reactor so he appeals to the part of Fusion who is opposed to it. Pinky replies that he can't stop Hubert, but he can try to separate them. So, Pinky tries to pull apart and, soon, Fusion looks like a glowing faceless set of Siamese twins. Two heads and four legs become visible but the twins are still attached. Pinky pleads with Spidey to help him separate. The wall-crawler steps in, trying not to think about what he's doing. He wedges his leg on their two backs and shoves the two heads apart. Using all his strength, he separates the men. Then, not knowing which is good and which is bad, he uses both hands to punch them... knocking both men unconscious.
Pinky and Hubert lie sprawled on the ground. Spidey realizes that they are "two harmless-looking midgets". In the end, he plans on taking them to a doctor, but he doesn't know what "an ordinary MD" can do to help.
For those wondering what happens with the Daily Globe and Rupert Dockery, check out the Lookback of ASM #210 as Spidey gets introduced to Madame Web.
As for what happened to Fusion... he never appeared again. Can we assume that Hubert and Pinky Fusser were somehow cured? Or are they being kept apart in some institution somewhere? We will probably never know since oblivion seems to be Fusion's lot... a suitable fate for a villain who might have succeeded beyond his wildest dreams if he had just spent all his time in New Jersey.