Richard Bruce, an American in fog bound London stumbles into the midst of international intrigue, with Rose Thorne, an innocent dupe. Together they try to unravel the mystery, enlisting the aid of a cat burglar named Holmes, who they bump into along the way.
| Actor | Role |
|---|---|
 Robert ArmstrongRichard Bruce | Richard Bruce |
 Helen MackRose Thorne | Rose Thorne |
 Ralph BellamyJim Steele | Jim Steele |
 Roland YoungHolmes | Holmes |
 John MiljanRegan | Regan |
 Laura Hope CrewsLady Rockingham | Lady Rockingham |
 Henry StephensonMajor Thorne | Major Thorne |
 Beryl MercerElsie | Elsie |
 Tyrell DavisGerald Fairfax | Gerald Fairfax |
 Frederick SullivanThe General | The General |
 Desmond RobertsHarvey, a thug | Harvey, a thug |
| CCharles IrwinBill, a thug | Bill, a thug |
| FForrester HarveyCoffee Wagon Proprietor | Coffee Wagon Proprietor |
 Marjorie GatesonMrs. Grace Thorne | Mrs. Grace Thorne |
 John WarburtonReggie | Reggie |
 George K. ArthurDrunk at Party | Drunk at Party |
 Zeffie TilburyNot listed | Not listed |
 Edgar NortonMaitre d'hotel | Maitre d'hotel |
 Tom RickettsNot listed | Not listed |