The first of the Mr Moto series of films starring Peter Lorre. Mr Moto joins an ocean liner headed for Shanghai and makes a friend of rich young Bob Hitchings (Thomas Beck), son of the liner owner. Criminal activity in the form of smuggling is taking place on the boat though Bob is pretty oblivious to it and only has eyes for Gloria (Virginia Field) - though she is involved with the criminals...
Mr Moto knows something is up though and uses his friendship with Bob to track down the gang led by Marloff (Sig Ruman). But who is the real mastermind behind the gang...
Although it gets a bit bogged down on board ship once we get to Shanghai the action hots up with Mr Moto having to evade various attempts on his life. Full of dated stereotypes of course but undeniably fun.