Serendipity is the act of making fortuitous discoveries by accident, such as purely random events that turn out to be in our best interests. The word was coined by author Horace Walpole, from the ancient Persian tales of the Three Princes of Serendip. The word came into common currency with the New Age movement that started in the 1970s, and even spawned a New York restaurant called Serendipity 3.

In 2001, it also inspired screenwriter Marc Klein (the pen behind the 2012 Julia Roberts fairy tale Mirror Mirror) to write an airy rom-com about Jon (John Cusack) and Sara (Kate Beckinsale), a couple of soul mates who are fated to be together - eventually. They meet in serendipitous circumstances, at Bloomingdales, when they both reach for a pair of cashmere gloves. With a glove in each hand, they are instantly smitten with each other. Unfortunately, both intend to buy the gloves for their current lovers.

Hold the phone. There’s your trouble right there. They are buying something as bland and boring as gloves for their current swoons? Obviously their existing relationships are never going to give them the same frisson they experienced just looking at each other in Bloomingdales, and later over a cup of hot chocolate in the Serendipity 3.

But this is a rom-com, after all, and in spite of spending a deliriously happy evening together, they run into another obstacle. Sara is a New Age girl, who believes in serendipity and fate, and wants to be sure they are really destined for each other. So she writes her name and phone number in a book, Love in the Time of Cholera, and he writes his details on a five dollar bill. Both are released into the wild, as it were, and if the couple find them again, then fate obviously intends them to be together.

Fate is in no hurry, however, and a few years later, Jon is still compulsively scouring bookstores, and Sara checking five dollar bills. Both are about to be married but the lingering memories of that meeting in New York continue to haunt them. Unknown to each other, both decide to take time out from their impending nuptials to try and put their ghosts to rest.

Airy and light as this movie is, it raises some important relationship questions. Do you believe in soul mates? Do you believe there is only one person in the entire world that is right for you, who you are meant to be with, and that no matter what it costs and who it hurts, fate will somehow bring you together? Perhaps the answer to this question says more about the person than it does about the nature of love. It certainly says a lot about Sara, who believes it so utterly that she is able to walk away from the man who may be the love of her life, into the night, and let fate take care of the outcome.

Jon is less sure, but he agrees to test the theory. On the night they first meet, he and Sara get on separate elevators, agreeing to pick a random floor. If they both pick the same floor, fate wins. Both independently pick floor 23, but while her elevator soars to its destination, his is cursed with the arrival of a small boy who presses all the buttons and sends the elevator on a wild goose chase. Jon gets to floor 23 too late. Sara, convinced that fate has denied them, has already left.

In rom-coms, best friends are an essential part of the plot. In this case, Jon has Dean (Jeremy Piven) and Sara has Eve (Molly Shannon). With besties in tow they both head off to New York to find each other. Jon winds up back at Bloomingdales, with an opportunistic counter clerk (the wonderful Eugene Levy), and Eve runs into an old friend, who just happens to be Jon’s fiancée. Sara and Eve get invited to the wedding, but of course Sara has no idea that the groom is her soul mate.

Then the coincidences start to pile up - Jon’s fiancée gives him a gift, fearing that he’s not that into her any more, and of course it turns out to be Love in the Time of Cholera, with Sara’s inscription on the fly leaf. Eve is given the fateful five dollar bill in change, mixes up her purse with Sara’s, and the bill falls into Sara’s hands. Yes, it all sounds contrived, but fate does work that way.

Cusack and Beckinsale are both seasoned and intelligent actors who make even the most implausible aspects of the plot seem plausible, and with some able support from the rest of the cast - especially Levy’s brief but highly amusing scenes - they give this confection a touch of sharpness that saves it from becoming too sickly sweet. It is never explained how Jon’s fiancée takes being dumped at the altar - perhaps she just shrugged it off as fate. Fate doesn’t always give you what you want - sometimes it takes it away from you.