After synthesizing a cure at the Emily May Foundation, Marvel's Spider-Man 2 players will need to administer it to Doctor Connors to help counteract the effects of Kraven's serum. This means heading over to the doc's house in Astoria, where they'll then need to solve a puzzle involving a piano in order to figure out what became of the Lizard after he returned home.
Marvel's Spider-Man 2: Dr. Connors' House Code (New Threads Piano Puzzle)
In order to find the four-digit code for the piano puzzle at Dr. Connors' house, Marvel's Spider-Man 2 players will need the help of a child's toy.