Shawn immediately goes to see Woody to make sure it was actually Despereaux's remains that were found on the boat. Woody presents a few items and leftover body parts, but Shawn still doesn't believe that Despereaux is actually dead. He is convinced he is faking it. But Woody says that the dental records match, and that the remains surely belong to Despereaux.
Shawn eulogizes Despereaux at the funeral even though he still believes that Despereaux is not dead. Henry then shows up with a piece of paper that tells Shawn that the SBPD has 100% confirmation that it was Despereaux's body caught in the explosion.
Shawn is devastated. He loses it at the podium, then shortly after, he is approached by Jacqueline. She wants the dagger and thinks that Gus and Shawn have it. She threatens them, but luckily they are saved by the presence of the SBPD.
Turns out, Shawn does have the dagger and his intention is for him and Gus to use it to find Yerden's secret core collection of buried treasure that Despereaux alluded to earlier. Gus doesn't want anything to do with finding this treasure, but Shawn keeps insisting, as he will not let Despereaux die in vain. Shawn and Gus's arguing escalates into a full on brawl between the two. The dagger flies out of Shawn's hands. Shawn examines the dagger and finds that a false cap has flown off the end of it, revealing a key.
They go back to the museum curator to question him further about Yerden's core collection. They show him a picture of the key and he tells them that a key like this odoesn't turn; it is a pressure point key that opens the lock by insertion — designed to open a secret wall inside an old safe, perhaps. The curator tells them that he has seen this type of lock at Yerden's estate — an estate that has been turned into a guided tour.
At the estate, Shawn sticks the dagger key into everything he thinks it will fit into. A slot in the fountain outside actually works and they realize that they have opened a secret passage that leads underground.
In the underground room, they are shocked to see Jacqueline pointing a gun at them telling them to pull the lever that will open the vault to the core collection. Shawn does so and they see a sign saying "Look Behind You" hanging on the wall in the vault.
Just then, Jacqueline is knocked out with a shovel... but by who? It's Despereaux!
It turns out Despereaux faked his own death by changing his name in the DNA base to someone else's. Shawn and Gus are beyond relieved. Despereaux presents what he found in the vault: a gold vase. Shawn opens the vase and finds Yerden's ashes. All three are disappointed by this. But Shawn quickly discovers that the collection is not in this vault, that it is in Yerden's actual resting place, a crypt near the estate.
They break in and they discover, lined in the walls, six wrapped paintings. They immediately think these paintings are undiscovered Michelengelo's and DaVinci's. However, when they unleash the paintings, they discover some really amateurish art... certainly not of Michelangelo caliber. They look at the artist's signature: "Harrison Yerden" — the paintings were his originals! His secret treasure was the art that he himself created. The three are severely let down by this.
After Despereaux says his final goodbyes to Shawn and Gus, they learn that the SBPD only uncovered five paintings from Yerden's crypt, not six. From this, Shawn realizes that Despereaux stole one of them. In the end, we see Despereaux stripping the top layer of paint off Yerden's canvas. Underneath, we see that the painting really was an original Rembrandt all along.