A burly man is trying to force me to eat an oyster. Beside me, a group of fancy dress Caesars are jostling with a herd of pantomime Norwegian cows (they have udders on their heads, for some reason).
They are all drinking glasses of Sauvignon Blanc.
I’ve just run 24 miles, I still have another two miles to run, as well as two final wine tastings, a morsel of steak to eat and a final ice lolly before I stagger over the finish line.
No, this is not a dream I had after too much cheese. Welcome to the strange and wonderful world of the Medoc Marathon.
For most of the year Bordeaux, home to some of the world’s most exclusive and expensive wines, is a little be po-faced. I suppose if you can sell wines for more than £1,000 a bottle, you can afford to take yourself rather seriously.
But for one day a year, the whole place cuts loose to celebrate the annual Medoc Marathon, which has become a gloriously barmy affair since it was first run 31 years ago.
The recipe is simple.
Take a normal marathon, all 26.2 miles of it, loop it through the world’s most celebrated vineyards and chateaux, throw in 20 wine tastings, exotic fancy dress, breakfast, steak grill and, yes, an oyster bar.
It’s dubbed the world’s longest marathon and they’re not kidding; whether it’s the regular pit stops or the sozzled runners weaving their way across the road, shouting “j’ai soif” as they approach the next chateau.
I’m pleased to say this is also a challenge that the British have risen to with typical courage and determination. Of the 9,000 or so runners, 1,600 of them are British, showing that we can never resist an idiotic challenge.
I admit I’m not a novice runner – I’ve clocked up well over a dozen marathons on five continents. But I’ve never experienced anything as chaotic, unwise and gloriously dotty as this.
The whole event is a mobile carnival, and a Premier Cru one at that. Race day started with breakfast at Chateau Pichon Baron, where the ever-hospitable director Christian Seely was pepping his running team with a final croissant, coffee and... a glass of Quinta Noval port.
“It’s sort of a tradition here,” explained Seely, whose wine empire extends to the renowned port house as well as Axa’s four Bordeaux chateaux.
The chateaux compete fiercely for the team trophy, and Seely had fielded a set of runners he hoped would bring it home and trounce his long-standing – and usually victorious – rivals from Brane Cantenac.
I wimped out on the fancy dress part of the event.
Read more: Discover the sweet magic of Sauternes
The forecast was for heavy rain and the last thing I wanted was to lug a sodden Batman outfit through the French countryside.
I determined to make up for this by taking part in everything else the race could throw at me – even that oyster.
The start line is in the small but world-famous village of Pauillac. Acrobats twirled from a great silver globe above the runners as we jostled our way forward.
Then it was off into mile after mile of gloriously manicured vineyards.
Round almost every corner another renowned chateau was on hand to offer sustenance, and even a rest on their immaculate lawns.
It wasn’t all plain sailing though; the scrum around the wine tables at Chateau Lafite was turning nasty and I was here for a run, not a scrap, so I gave that one a miss.
The wine was not said to be up to much anyway. As a general rule the more prestigious the chateau, the worse the wine, confided Seely after the race, proud that Pichon Baron had served proper bottled wine rather than something dredged from a barrel.
A special award should go to Chateau Phelan Segur, which served a very decent glass of its 2008 second wine, Frank Phelan. I stopped and savoured that one.
The first half of the race flew by. Between the chateaux there was just so much to gawp at, whether it was the outlandish costumes or the gorgeous countryside.
But a marathon is a marathon, no matter how many jazz bands and food stations litter the way, and the miles began to take their toll on the runners.
After half way the rain started to fall, dampening spirits, apart from that damned irrepressible herd of Norwegian pantomime cows, who were still jostling their way round.
Still, the route wound through little villages and hamlets that the wine trade has made world famous – Beychevelle, St Julien and finally Bages.
I stopped at Pichon Baron to learn, a little disconcertingly, that the team runners were already enjoying their lunch and that Christian Seely had called it a day half way round.
Sadly his plans of team victory were dashed, despite scoring a second and seventh place in the race, by the unfancied Chateau de Villegorge who managed to get all five of their runners in the top 13.
Back at the more pedestrian end of the field, I carried on manfully after the oyster towards the finish.
At this point a special raspberry deserves to be directed at Chateau Latour, the grandest of them all, which kept its gates firmly and miserably shut for the whole event.
A few more hundred metres and a turn to the right and I was across the finish line by the banks of the Garonne, where I was handed a medal in the shape of a bow tie and a commemorative bottle of wine.
Then it was straight off to lunch in a tent that offered more… yes you guessed it.
Medoc may not really be the longest marathon in the world – it’s exactly 42.2km, just like all the others – but it’s certainly among the slowest.
I finished in a shade under five hours, which put me in the top quartile of the field.
Others were still waddling their way to the end an hour and half later. And why not, when there was so much fun to be had out there on the course?
Now I only have one athletic ambition left in life – to get the Team Pichon Baron call up in 2016.
City A.M. Wine Club - Whether you’re an investor or an oenophile, joining City A.M.’s wine club can help you build your perfect cellar. Find out more here.