An old Scotland Yard Inspector friend Montague Shaw drops in on Charlie Chan in Honolulu asking for his help in catching a murderer whom he believes is on a cruise bound for San Francisco. Shortly afterward Shaw is strangled and Sidney Toler now has a personal reason for taking over Shaw's investigation.
Also coming along is Number 2 son Victor Sen Yung as usual providing his unwanted assistance to Pop. Number 2 son as a stowaway earns his passage as a steward's assistant, but does prove useful in being able to search cabins of cruise passengers.
With such worthy villainous types as Lionel Atwill, Leo G. Carroll, Charles Middleton, and Leonard Mudie in the cast it's going to be difficult to tell who the perpetrator can be. All have been cast as villains in many films. Jewelry salesman Don Beddoe also winds up dead before the cruise is over.
With a really good cast to provide believable red herrings Charlie Chan's Murder Cruise is a top drawer feature of the Charlie Chan series. Captain Stubing never saw things like this going on with the Love Boat.