This week Castle visits a Prohibition era bar in search for a secret stash of liquor that people would literally kill for. In the process, he meets a young billionaire he'd like to punch and serenades Beckett with Billy Joel.

It's brand new day in New York and guess what? Another body has turned up in the East River! And it looks like he was bludgeoned by one seriously expensive bottle of scotch, one that even Castle would kill to get his hands on. Unfortunately, the only bottle in existence has just been bought by a certain start-up billionaire that doesn't have much of an appreciation for fine liquors.

Later, Castle and Beckett get to explore their inner Indiana Jones, as they make their way through the old New York sewer system in search of a former mayor's infamous hoard of the finest alcohol in the city.

In the end, Castle finally gets a taste of that scotch, but not before beginning a group sing-along! If you've ever seen Dr. Horrible, you know that Nathan Fillion can sing. But... what about the rest of the Castle cast? Check out their rendition of Billy Joel's classic "Piano Man".