By chance Mike finds out about the wrongs names, goes to San Francisco to inquire about them and just comes back when their boat is leaving the harbor. He holds onto the boat and – undiscovered – goes along heading for Alcatraz.
He watches them taking a spare diving suit and a scuba along when they dive into the sea. The brother – waiting at the shore – is ready to dive away from the island to the boat. While two other brothers get ready to fetch him, Mike overwhelms one brother, signalizes to the prison staff and overwhelms the other two in underwater fights.