The Mysterious Music Box in Bloomington, MN

Steve, Matt, and Jenny thought their new case would be a cinch. They were wrong.
What starts out as a search for a stolen music box quickly turns into a dangerous hunt when the three detectives discover the dark and mysterious history of the music box and a secret that could lead them to a fortune of long-lost gold from World War II.
As the trio delves deeper into the mystery, they encounter two nefarious thieves, both willing to do anything to get their hands on the missing gold, including eliminating the competition. Racing against time, the trio must figure out the meaning of a clue left behind by a dying man in order to keep the music box, and the gold, out of the hands of the deadly treasure hunters.