The episode begins with Neal lugging knockoff watches to the FBI building, where Sara stands waiting with information about a sunken U-Boat off New York coast that Peter thinks Adler is after.
When Mozzie finally launches the fractal antenna they find that it’s unsuccessful. Neal attempts to call Alex, only to hear Adler pick up and threaten Neal if he doesn’t “call off his dogs.”
While searching for Alex at the Conservatory Gardens, Neal and Peter get captured by Adler and are forced to drink a knockout serum.
Neal wakes up to find Alex hovering and Peter already awake. They find that they are in a warehouse where the lost U-boat Adler was looking for has been brought from the surface and placed there. Neal has been captured to try and open the hatch without tripping the self-destruct mechanism.
Trying to meet Neal, Sara comes to his apartment, where Mozzie is working on his fractal. They get suspicious when Neal doesn’t arrive. In the meantime, Diana and Jones become suspicious as well and it’s decided that all four of them will go out and search for them.
Neal and Peter struggle to open the hatch without tripping explosives attached to it. When they attempt to cut the wires to bypass an archaic typewriter they trip a timer. Alex remembers her grandfather’s story about Midas and she reveals that her father was the one who received the SOS signal of the U-boat before it went down. Adler also reveals that his father was the only person to survive the U-boat sinking.
Neal and Peter embark down the hatch to find the greatest art collection of their time.
After finding the treasure, Adler leaves Neal, Peter and Alex in a dry dock, bound at their extremities as water comes up around them. Alex managed to steal a knife from their captors, which they use to untie themselves. Jones and company arrive just in time to save the three from a firestorm when they attempt to escape.
Neal and Alex share a moment in which the two kiss, Mozzie and, more importantly, Sara are inadvertently exposed to it.
Back at the FBI it’s decided that they will go in with a team the following day and check out the industrial district to find where the U-boat is stored. Neal begins looking on his own and runs into Adler who tries to con Neal into helping him.
Unexpectedly the warehouse explodes and the two try to open the door to but are unsuccessful. It’s obvious that the U-boat is a total loss. Adler, angered by what he thinks is Neal’s revenge, threatens to kill him. Peter shoots Adler dead.
As the fire continues to smolder a piece of a painting, the same one of the Chrysler building Neal was working on at the apartment, falls to the ground in Peter’s line of sight, who is quick to accuse Neal of being behind the blast. They argue momentarily, but Neal challenges Peter to prove it before walking away.
Neal returns to his apartment to find a key and a note with an address for a warehouse on it. Neal visits the address to find all the treasures in perfect condition.
But it’s the sly smile that crosses Neal’s lips that has us wondering: Could he have actually been behind this?