After holidaying in Ireland, Peter Weston, a London music department sales clerk and aspiring songwriter/musician, meets Irish lass Moira O'Shannon aboard the overnight sailing back to England, and attracted to her, offers her a ride back to London once they dock, which she accepts. His attraction to her is despite he already being engaged to Vanessa Colebrook, the daughter of wealthy Sir James Colebrook, Peter himself not coming from wealth which may be an issue for Sir James. Peter's attraction to Moira to some extent doesn't matter as Moira too is already engaged, her fiancé Albert currently working in South America. By the time Peter and Moira are ready to disembark the ship, Peter has reluctantly inherited something: a live alligator named Daisy, albeit a tame one. While Peter, who in general is scared of reptiles, wants to get rid of her in any way he can, Moira does whatever she can to ensure he doesn't, she an animal lover in being an animal keeper at the London Zoo. As Peter figures out what to do about Daisy, he gets into one misadventure after another, with some having a similar initial reaction as his when first unexpectedly meeting Daisy, while he also discovers some like Moira who have an affection for Daisy. As Peter becomes attached to Daisy himself, the triangle that ends up being himself, Vanessa and Moira becomes more pronounced as he continues to hide Daisy's existence from Vanessa. That triangle ends up being a square of sorts when Albert returns from abroad, he not quite as Moira had depicted him.