Professor Power had double agents in the New York S.H.I.E.L.D. headquarters free Leviathan, Mad Dog, and Mutant Force from S.H.I.E.L.D. custody, and sent Leviathan against the Defenders.
Professor Power had spies working for him within the New York S.H.I.E.L.D. headquarters, freeing the villains Leviathan, Mad Dog, and Mutant Force from custody, and sending Leviathan to fight the Defenders.