Spider-Men is a side mission in Marvel's Spider-Man. A local business owner thanks Spider-Man for saving his daughter, only he has no idea what the owner is talking about, and investigates the scene, suspecting a Spider-Man imposter.
Spider-Man finds a local business owner who thanks him for saving his daughter. Confused, Spider-Man looks to the crime scene to investigate, seeing a cop along with some beaten thugs. The owner's daughter, present at the scene, asks why he is still there and not off to stop the nearby fire. Spider-Man plays along and tracks the fire where the imposter had saved people, and upon investigating a fire extinguisher that the imposter used, identifies a substance on it as Ammonium Dihydrogen Phosphate, which can be used to track the imposter. Spider-Man concludes the imposter is clearly trying to do good, but by using his costume without his powers, is putting himself in great danger.
Spider-Man eventually finds the imposter accosted by Wilson Fisk's men, and rescues him. The two fight Fisk's men together, and the imposter reveals he is actually a local martial arts teacher teaching at Chikara Dojo, just trying to "spread the legend". Spider-Man convinces him to help out by going to the local F.E.A.S.T. shelter and offering free self-defense classes and instead leave the crime-fighting to the real Spider-Man.
After talking to the business owner, head to the theater, the first crime scene. The daughter is still at the location just in front of the entrance to the theater, as are the cop and the defeated but breathing thugs. Talking to the daughter reveals a Spider-Man imposter heading south to check out a fire. Examine everything at the scene then follow the next waypoint to the fire.
Locate the fire scene and check for evidence and clues. Firemen, a civilian, and a fire escape can be examined. A fireman is looking for a fire extinguisher, which is located just to the right of the building entrance. Investigate it and solve the mystery of the unknown substance. The substance is identified as Ammonium Dihydrogen Phosphate, a fire suppressant. Spider-Man is able to use the chemical signature to track "Spider-Man 2.0".
The trail leads to a drug deal scene. Interact with the arrested thug at the end of the trail, then climb to the roof of the nearby building and examine the thugs and the drugs. After this, head to the edge of the roof, where Spider-Man finally catches up with the imposter, finding him held at gunpoint by some of Fisk's men. Jump down and rescue him, then defeat the thugs. The thugs arrive in two waves, and the imposter will help fight in melee combat, though Spider-Man will have to do most of the heavy lifting, particularly against thugs with firearms and rocket launchers.
Once the side mission is cleared, the location of the final battle becomes the location of a Fisk Hideout.