Also Read: Here Are the TV Shows and Movies That Will Be Available on Peacock at Nationwide LaunchThe plot kicks off when Shawn and Gus set out to discover why Juliet’s partner at the San Fransisco police department, Sam Sloan (Sam Huntington), is shot by former police informant Billy (played by Zachary Levi) — or The Thin White Duke, as Shawn and Gus call him.