While Charlie is distracted with the birth of his first grandchild, son Jimmy impersonates his father in order to investigate a murder aboard a freighter in the harbor.
| Actor | Role |
|---|---|
 Sidney TolerCharlie Chan | Charlie Chan |
 Phyllis BrooksJudy Hayes | Judy Hayes |
 Victor Sen YungJames Chan | James Chan |
 Eddie CollinsAl Hogan | Al Hogan |
 John 'Dusty' KingRandolph | Randolph |
 Claire DoddMrs. Carol Wayne | Mrs. Carol Wayne |
 George ZuccoDr. Cardigan | Dr. Cardigan |
 Robert BarratCaptain Johnson | Captain Johnson |
 Marc LawrenceJohnny McCoy | Johnny McCoy |
 Richard LaneJoe Arnold | Joe Arnold |
 Ruth CliffordNurse | Nurse |
 Layne Tom Jr.Tommy Chan | Tommy Chan |
 Philip AhnWing Foo | Wing Foo |
 Paul HarveyInspector Rawlins | Inspector Rawlins |
 Grace LemMama Chan (uncredited) | Mama Chan (uncredited) |