ON AN unexpectedly balmy evening, Ali Kefford and Siobhan McNally boarded The Gin Train for its inaugural journey on the Watercress Line, puffing between Alresford and Alton. And back again, several times.

The 242 passengers had paid £75 a head for an exclusive evening of fine dining from the best tapas this side of northern Spain from Alresford restaurant Pulpo Negro, accompanied by gin cocktails from the Winchester Distillery.

It would prove to be a nostalgic trip back in time, complete with a whiff of drama and dollop of intrigue.

There had been something of a party before departure, with laughter swirling around the sun-splashed platform as passengers sampled Twisted Nose Watercress Dry Gin cocktail in glasses goldfish would be happy to call home.

It was the sort of fleeting happy-go-lucky atmosphere you expect from a vintage Whodunnit, moments before a gruesome murder involving a woman wearing suspiciously bright red lipstick, an absent-minded gardener and a copy of Who’s Who In New-Alresford-Much-Older-Than-Old-Alresford-Actually.

Steaming through Ropley (for the third time), the lights abruptly flickered and died, and diners in the plush first class compartment were plunged into darkness.

“Oh my goodness, I’ve gone blind!” shrieked Winchester journalist Siobhan, clutching imaginary pearls in one hand and a Bramble G&T in the other.

“Just how many of those gins have you sunk?” naval hack Ali remarked archly. “The lights will come back on in a minute - the engine driver probably needs to shovel more coal on the fire or something.”

“Engine stoker,” corrected Siobhan, adjusting her burgundy alice band. “And a rather sexy stoker at that. Did you see the way he undressed me with his eyes when we inspected the steam engine earlier?”

Rolling her eyes in the dark, Ali said drily: “I think you’ll find his pained expression was a silent cry for help. And can you please keep your hands off my gin!”

“But I haven’t touched your...,” Siobhan exclaimed before she was interrupted by the lights spluttering back into life.

The babble of conversation rose again as diners returned to their main course of tender Moorish spiced pork skewers served with smoked aubergines, flame-grilled peppers, chickpeas and confit onion salad.

But it was soon apparent that under the cloak of darkness, a dastardly deed had been committed.

Drawing on years of experience spent supping watered-down-wine in Whitehall’s seediest bars, submarine specialist Ali noticed in seconds that something was amiss.

“Where’s my cocktail garnish?” went up her shrill hue and cry.

The entire carriage went quiet until all that could be heard was the gentle chuffing of the engine and the sound of fingers tapping on smart phones.

“Shhhhh,” whispered Siobhan, while trying to remove the incriminating seeds of a Mediterranean-grown blackberry lodged uncomfortably between her back teeth.

“I will not rest until I solve The Case Of The Missing Cocktail Garnish. But something tells me the perpetrator of this great garnish train robbery is sitting right under my nose,” she glared. while stroking what she feared to be the beginnings of a menopausal moustache in a knowing Belgian detective way

Luckily just then, the guilty party was saved by a flurry of activity from the waiting staff as the clinking of tonic bottles indicated the drinks trolley was making its way through the train once more.

This was timely as the thirsty group opposite were by now on vapours.

“Lordy, did they just order trebles all round?” stage-whispered Siobhan. “I fear last time this happened in our buffet car, they ran out of hot Bovril.”

“But now that they’ve opened the flood gates, I think I’ll have one of those too, thank you,” she continued, more loudly.

Sitting back contentedly, the scribe patted her well-upholstered chair and mused: “Lest we forget the important contribution soft furnishings made to the war effort.”

Then promptly fell into a deep sleep – years of being at the beck and call of a national features editor, plucking gags out of the internet and passing them off as her own, finally taking its toll.

Finally The Gin Train drew into Alresford for the last time, and hundreds of merry passengers disembarked into the car park, weaving their way round suited station staff, some of whom looked like they had been wearing their uniform since VE Day.The Watercress Line had found a new twist to its repertoire. But most importantly The Mystery of the Missing Cocktail Garnish had been solved - even if Siobhan did require extensive dental work several days later.