|Trophy: Staying Positive|
The Heart of the Matter is the forty-third main mission in Marvel's Spider-Man. With the information Mary Jane Watson gained about Norman Osborn's secret lab, Spider-Man heads across the city in an attempt to find the Devil's Breath antiserum. This is the penultimate mission of the story.
Spider-Man heads off to retrieve the antiserum. Along the way, Yuriko Watanabe calls and informs him that a helicopter just went down at the address of the secret lab.
Mister Negative has captured Norman, and his Inner Demons patrol the ground and rooftops outside. Players need to take out as patrolmen as possible using stealth before getting into a direct fight. Sable International troops also show up with their jetpacks. At the culmination of the fight, Silver Sable appears. Listening to Spider-Man's logic, she finally decides that they are better off working together rather than against each other and agrees to a temporary truce until Norman is secure. She allows him into the building.
When Inner Demons show up outside, she stays behind to fend them off, leaving players to follow Li's trail through the building. Players should be careful when contacting the areas of negative energy, as they can cause significant damage. Li gets the jump on Spider-Man as he enters the lower level, and players are once again put into the "negative zone" in order to chase Li. When he exits, Norman is screaming in the other room.
After attempting to intervene, players then face off against Mister Negative. His skill set has increased since the previous battle, as he now wields an electrical blade and is swift moving. Hurtling debris at him helps, but webbing does not. Players need to keep mobile. At one point, Mister Negative succumbs to transforming back into Li, but he resists. He forms a giant demon made from negative energy, which summons an army of negative souls to assist in the fight.
The player then returns to the negative zone. Once the initial enemies are dealt with, the demon will return with a sweep attack that must be dodged. It will make more appearances as the fight continues, summoning more enemies. Staying airborne and using debris to smash into Mister Negative works well as it makes most of the attacks can be avoided.
Upon Li's defeat, Doctor Octopus enters the room. Via cutscene, he fights Spider-Man and knocks him out, taking the antiserum for himself. He then takes Norman and heads out of the building. Silver Sable rushes in moments later to find Spider-Man on the floor, mortally wounded. They take him to F.E.A.S.T., where Dr. Morgan Michaels works to save his life.
Though he is saved, Spider-Man insists on finding the antiserum before resting, especially when he learns Aunt May is sick and in bed from the Devil's Breath. Mary Jane insists he use his brains to defeat Otto rather than relying solely on his spider-powers. At the scene's end, a spider from Osborn's lab that hitched a ride on Mary Jane's coat bites Miles.