The Jeffersonian team unravels an unexpectedly competitive world of mini-golf as they try to piece together the murder of the sport’s superstar. Meanwhile, Brennan is worried her father Max is reverting to his criminal tendencies and “squintern” Wendell Bray, enlists Hodgins to help him fix his girlfriend’s family heirloom.
Castle and Beckett discover an ER doctor who was gunned down in the street was a mob doctor to a mafia family with ties to Castle; Esposito and Lanie reach an important moment in their relationship.
A nefarious virus is uploaded to Walter's computer, turning the team's new "smart" building project into a death trap with people locked inside.
The crew and eccentric passengers of a budget airline take a roundtrip flight from Los Angeles to Las Vegas.