What is it about New York that inspires such creativity? If you’ve never been there, you imagine the bright lights, the yellow cabs, the wisecracking cops, the Broadway shows; Macy’s and Bloomingdales; the art deco elegance of the Empire State Building, the upright nobility of Lady Liberty, carriage rides around Central Park. You imagine all the movies, all the TV series, all the plays that have their roots there. You imagine you are part of one giant creative hub. Go to New York and you will make your fortune, become a star, make your dreams reality.

Whereas, of course, if you’ve been there, you know that the truth can be somewhat different. Yes, all those fantasies are possible; but if you’ve not much money, are working unsociable hours in a coffee shop, sleeping on a friend’s sofa, you can put all thoughts about glamour and showbiz out of your head, and like as not you won’t be welcome in Macy’s.

Fantasy meets reality in Jim Barne and Kit Buchan’s new musical, The Season, appearing for a couple more days at the Royal and Derngate, a co-production with the New Wolsey Theatre in Ipswich, where it has already played. Dougal has flown from his home in Northampton (and why not) to New York for a weekend to attend the wedding of his long-lost Dad, who left the matrimonial home months before Dougal was born, to seek his fortune in the Big Apple. Dad is marrying Melissa, decades his junior, the old rascal. Dougal has romanticised the opportunity finally to meet his father to a heart-palpitating extent; he has fantasised about discovering an extended family, being part of somewhere glamorous, and doing all the things that a boy and his dad should do.

He’s met at the airport by Melissa’s sister Robin; she’s been tasked to do this, just as she’s been dogsbodied to get the wedding cake from the bakers, buy her sister’s last-minute wedding stockings, and, one senses, a lot more. But Robin has a busy schedule of her own. Her reality is the Bump and Grind coffee shop; and if she doesn’t work, she doesn’t get paid. Managing the over-enthusiastic puppy that is Dougal is the last thing she needs. But over the course of the weekend life changes for both, in part due to his high-pressure tactics, in part due to her need to escape her doldrums. His fantasy becomes overtaken by reality, and her reality gains a glimpse of fantasy. But in which direction will the future turn? I’ll say no more about the plot, but let’s just say that neither of them could have predicted the outcome.

In many respects The Season reminded me strongly of that old Marvin Hamlisch musical, They’re Playing Our Song. Both have two characters, set in New York, where an incompatible couple find themselves attracted to each other and we see them deal with the consequences. And in both shows, the future for the two people is uncertain. But there is an element of melancholy in The Season, absent from the more showbizzy TPOS, that gives it depth and reflection. You sense there is so much in The Season that is left unsaid; there is eloquence in those gaps that really encourages your imagination to work hard to get a full appreciation of these two people’s lives.

Amy Jane Cook has created a brilliant set, with a centrepiece of New York bright-light signs, a stage strewn with subway signs, and a inventively used revolving stage to help give a sense of progress through the city, but which also subtly tells some stories of its own; the sequence of drinks and food trays that emerge from behind the set, for example, that explain the night at the Plaza, fills in so many details without a word being said. Grant Walsh leads a trio of musicians who provide a fabulous soundtrack to the developing story with a depth that would suggest many more people backstage.

Tori Allen-Martin and Alex Cardall create a perfect onstage partnership, with their characters’ clear, opposing personalities driving the show on with great power and vigour. Ms Allen-Martin’s Robin is a deeply troubled soul but you only get to realise this on a dripfeed basis as the show progresses; and we all get to enjoy her revenge by credit card activity. Mr Cardall is a bright, happy stage presence; an innocent abroad who takes a childlike pleasure in the simplest of activities – in fact, someone we could all learn from. The scene at the beginning of the second Act perfectly portrays the difference between the two characters; one confused, horrified, nauseous and exhausted, the other as though he were auditioning for a Kellogg’s Fruit and Fibre advert. The pair of them are both hilarious and alarming in turn; over the course of two hours you feel you’ve got to know them intimately as friends and, frankly, you worry about them.

Social media is already demanding The Season 2 – will we find out what happens to Robin and Dougal? I rather like the fact that all their experience is contained within one weekend; that it’s one big finite flourish of experience that they can take home with them and use to enhance their separate lives. But a sequel would be good too! Hopefully this isn’t the end of the line for this fascinating couple. A fantastic little nugget of musical delight.