New York, 1955. The mafia is fighting for control of the city. Then something stranger starts happening: five mafia bosses vanish without warning. At each disappearance site, investigators find a strange liquid residue and a butterfly. Before anyone processes what that means, children begin disappearing too—each one having drawn the same butterfly image before vanishing. Detectives and journalists converge on the mystery from different directions. The mafia problem and the butterfly problem are connected. The question is how.