Nick Spencer's Amazing Spider-Man run has brought Peter Parker and Mary Jane Watson back together, but it looks like their reunion will have consequences . Harry Osborn's transformation into Kindred is chief among them, and it seems he wants to hold his best friend accountable for the decisions he made during One More Day.
In that controversial storyline, Peter gave up his marriage in a bargain with Mephisto to save Aunt May's life. That also led to Harry's resurrection, and the trauma of being pulled back from Hell (remember, he was the Green Goblin when he passed away) could be why he's Kindred now.
At the end of today's Amazing Spider-Man #60, Doctor Strange does some digging and meets with a mysterious figure who claims to have no knowledge of Kindred's existence. It's then we learn that the Sorcerer Supreme is talking to Mephisto, and that there's something wrong with Peter's soul.
That sinister smile points to Mephisto remembering his deal with Spider-Man, and there being bigger ramifications for Peter than we realised coming out of that arc.
Spencer is taking a slow burn approach to this storyline, and it wouldn't be surprising if it doesn't pay off until Amazing Spider-Man #900 (the next run will put the spotlight on Spidey's battle with Mayor Wilson Fisk).
Check out the shocking last page below: