Spider-Man swings through New York with a bottle of barbecue sauce for Aunt May and going through the rest of his "to do" list involving picking up Mary Jane and paying rent. He notices two window washers in jeopardy when the cables from their platform snap. As he swings in and saves them, the platform continues to fall toward a giant cooling tank full of Freon.
The platform hits the tank, causing a tidal wave of Freon to rush over to a nearby roof where a mother and daughter are hanging out the laundry. He sets the window washers on a nearby rooftop and dives to save the mother and daughter. For his trouble, he is exposed to a lethal amount of the chemical, his heart stops, and has an out of body experience.
His soul observes his physical form lying motionless and begins to reflect on his life with the perspective that death gives. He realizes that he spent his time worrying about everything and as a result never enjoying life to the fullest.
His essence rises above the rooftops, the city skyline, and past the clouds. As he continues on his journey toward "The Light" he realizes that he's overwhelmed at the prospect of seeing Gwen Stacy again. Much more so than leaving Mary Jane behind.
He quickly arrives at junction point where symbols from all religious denominations converge to form a single afterlife. Mythological items, religious symbols, and other spiritual tokens converge into what Peter calls a religious junkyard. Peter muses that this is the altered state that enlightened people seek, and is a bit disappointed. Just as he arrives at the prospect of this being limited by his mind, he encounters Thanos - who is in possession of the Infinity gems - and the embodiment of Death. Thanos explains that only those claiming to be "heroes" warrant this level of attention. Their lives are spent in a futile effort to save lives already claimed by death.
Thanos creates a window back into reality and shows him the results of his latest heroic act: saving the woman and her daughter from the Freon. The woman is standing near the body of Spider-Man, saying that she hates him while cradling her daughter. She was exposed to the freon as well and is also in a near-death state. To prove his point, Thanos shows him that the daughter has appeared in this realm. Peter demands that the girl be released from Death's grip. Thanos claims that it is impossible.
Impossible or not Peter attacks Thanos to force him to release the little girl. Thanos' claims that "nothing is solved physically" in this realm and that "beyond death there is no will or desire" fall on deaf ears as they continue to fight. Thanos tells Peter that his efforts as Spider-Man were a complete waste of time. The only result from his "heroics" is ultimately the creation of more villains who in turn cause more misery and destruction than he could ever possibly correct.
Death eventually separates them. After some consideration into the matter, she agrees with Peter and – much to Thanos' dismay – releases both of them from her realm.
Once Spider-Man wakes up, he realizes that the daughter is still alive and in need of medical attention. With a grateful mother's appreciation, he takes her to the nearest hospital and immediately begins to worry because the bottle of barbecue sauce for Aunt May shattered during the rescue.
I'm not the biggest fan of Ann Nocenti, so this may be a bit biased. To her credit, she did create the Typhoid Mary, Blackheart, Mojo, and to a lesser degree Longshot. Those are significant contributions, but the rest of her work that I have read is very average.
Discussing the afterlife of a superhero is interesting, to me at least. Trying to see where they fit on the karmic continuum and taking into account their unique circumstances opens up the potential to see these characters in a new light. Unfortunately this story didn't try to delve into that.
There was something missing in the execution. Granted this had to fit into a single issue, but this was skimming the surface of the subject and failing to present one truly compelling idea. The religious junction point was nice, but I've thought along those lines for years. This is the what separates the average writers from the great ones: the ability to open up new areas in a limited space.
What could have been a unique story delving into the actual soul of Peter Parker comes across as "Spider-Man fights Thanos in limbo and breaks a bottle of barbecue sauce". A few good ideas are presented, but nothing Earth-shattering.
I did however like Rick Leonardi's artwork. That is the sole element that makes this tolerable. However there is only so much that one can do with a mediocre story.
For good examples of the "soul scouring" type of story, check out Incredible Hulk (Vol. 1) #312 which takes a detailed look at the life of Bruce Banner before he became the Hulk. Another good example is Amazing Spider-Man #274 in which the fate of the universe depends on Spider-Man's moral compass.