The series picks up shortly after the events that concluded the Amazing Spider-Girl series. Spider-Girl breaks into the abandoned headquarters building of the Order of the Goblin to investigate and find some answers about their former leader Norman Osborn's plot to control her father Peter Parker and unleash a symbiote hybrid clone of May. May's clone arrives, having followed her from their home where the Parker family has agreed to take her in, and shortly there after they discover explosives rigged to destroy the building. Both girls narrowly escape the building before it explodes.
May's clone uses her symbiote powers to create a blue and black costume to mimic May's own costume but distinguish them as two separate Spider-Girls. The two happen upon a fight between rival gangs and subdue them but May must stop her clone who is overly aggressive and seemingly willing to kill her enemies as she threatens one goon with her razor claws.
The Black Tarantula, the current Kingpin of Crime, and Arana are recuperating from the recent events in Amazing Spider-Girl. Black Tarantula's assistant Chesbro informs him that someone is challenging him for control of the New York underground.
Don Silvio "Silverback" Baracca has summoned Man Mountain Marko to his estate to reveal his paralysis has been cured with adamantium skeletal structure enhancements and he is ready to challenge the Black Tarantula for position of kingpin.
Back at the Parker home the family discusses what to do about May's clone's continued life in their household. She uses her symbiote powers to create a new look for herself to distinguish her from May and then takes a new identity as May's cousin, April Parker so she can join her at Midtown High. April later makes a flashy entrance at school that gets the attention of May's friends as well as the rest of the high school.
Meanwhile, Rene DeSantos is informed that Fury the Goblin Queen has escaped from the sanitarium where the Order of the Goblin was holding her.
That evening back at the Parker household a young woman arrives at their door with a striking resemblance to Gwen Stacy and claiming her name is in fact Gwen Reilly. Gwen tells her story that she is the daughter of Ben Reilly, May's "uncle" and the clone of Peter and was born only a few months after Ben had left for New York. Her only contact with her father were letters he had written to her from the road when she was too young to read and has now only recently discovered. She has come to the Parkers' to learn of her father and to see his grave. Believing that she is lying May slips a spider-tracer into Gwen's jacket pocket so that she can follow her once she leaves.
May and April leave swinging over the city skyline tracking down the spider-tracer that is planted on Gwen Reilly. The two Spider-Girls come across a gang fight and May leaves to take care of it and sends April to continue on to track down Gwen. May is able to subdue the gangs and returns to pursue April and find Gwen and it's not long before she hears a blood curdling scream and swings down to investigate. What May finds is Gwen Reilly laying dead in an alley, her stomach slashed, and April standing over her with her claws out.