Englishman Robert Gregory, an understudy in a Broadway musical, gets an opportunity to play the leading role on the eve of his deportation from the country.  En route to the boat, his taxi collides with another cab that is carrying Patricia O'Malley, who is also headed to the boat to marry Charles Gardner, an eccentric millionaire she doesn't love.  It is a case of love at first sight, and they are very much relieved when they discover that they have missed the boat.

Meanwhile, aboard the boat, Pat's tardiness prompts Charles to believe that he has been jilted, and accompanied by his butler, Griggs, he disembarks before it sails, while Bob's absence prompts the immigration authorities to issue a warrant for his arrest.  Learning of Bob's jeopardy, Pat insists that he spend the night at her Uncle Luigi's, where he immediately wins the favor of Pat's kid sister Mary.

The next day, Charles begins a campaign to win Pat back, and sends Griggs to Sascha's restaurant as an ambassador.  To disrupt the peace talks, Bob pretends to be a waiter, and Griggs finds his face vaguely familiar.  After Griggs departs, Bob proposes to Pat and she accepts.  That night at dinner, Pat tells Charles of her decision, and Briggs, finally recognizing Bob as the fugitive whose picture appeared in the paper, suggests that they turn him into the police.  When Charles, always the gentleman, refuses, Griggs plants a story in the paper about the wife and three children that Bob has left behind, causing Pat to return to Charles.

Meanwhile, Bob, dejected, learns that Sascha is threatened with eviction and offers to turn himself in while performing on Andre Kostelanetz's new radio program.  As Pat despondently listens to the sound of Bob's voice over the radio, Charles realizes that she still loves him and, upon learning of Griggs' scheme, reconciles the lovers and adopts Bob to make him a citizen.