"A pal of mine sent me a text this morning saying, 'I'm wishing you the worst day in bookmaking history.' Which I thought was quite good." – Willie Mullins, Tuesday, March 10th, 2015

From a long way out the 2015 Cheltenham Festival was – to mangle a famous old racing headline – Willie Mullins First, The Rest Nowhere. Plenty of trainers had had plenty of good horses before, but what Mullins was sending over this time around was close to vulgar.

He didn’t just come armed with a bagful of favourites across the week – nine in total before it all kicked off – he had a job lot of short-priced ones. Any fewer than five winners would have had people talking.

If most of horse racing is a mystery to the broader sporting public and the Grand National is for everyone, the Tuesday of Cheltenham is somewhere in the middle.

It helps to know a bit about what you're watching, but you don't necessarily need to know a lot. It's a day off booked a couple of months in advance, it's the Racing Post all morning, and a guiltless pint sitting in front of you by midday. By the time the tapes go up for the Supreme, it's a frenzy.

For bookmakers, a frenzy is dinner time. Bookies can generally deal with professional gamblers by keeping them where they can see them and refusing to take their bets if the liabilities are too high.

But when it comes to Cheltenham they’re generally only too delighted to see once-a-year heroes stitching together all the doubles and trebles and accumulators they can think of because the only dead cert is the fact they won’t all win.

This was different. Or at least it had the potential to be different. This was an army of casual punters seizing on four short-priced favourites from one trainer on one card on one of the biggest betting days of the year. Douvan, Un De Sceaux, Faugheen and Annie Power. All trained by Willie Mullins. All ridden by Ruby Walsh. All indisputably the best horse in the race.

These planets aligned to make Tuesday, March 10th, 2015, a day when the bookmaking industry in the UK and Ireland genuinely faced clear and present danger. For the rest of us, whether there was money down or not, it was the most dramatic piece of sporting theatre all year.

“People who never heard of Kauto Star were jumping on this accumulator”

Ruby Walsh: "I had four great rides and breaking them down individually, you could see why each one would win. But when you put them into a collective, you're thinking, 'it's Cheltenham, it's very competitive and nobody has ever ridden four winners in a day at the festival before.' When you looked at it that way it looked far more complex. But individually, yeah, you could see how each of them would win."

Hayley O'Connor, Ladbrokes: "Because Willie has horses who are so far head and shoulders above the others, accumulators are the only option ordinary, occasional punters want to know. They didn't want to back Un De Sceaux at 4/6 and Faugheen at 4/5 and Annie Power at 4/7. But they liked the idea of putting them together."

Patrick Mullins: "My first memory of Cheltenham is bringing Florida Pearl over to the Gold Cup. I was nine years old, and Florida Pearl was my hero. I was going there thinking that this is our superstar and he can't get beat. And all I remember is coming home so disappointed. So that's the first and most important Cheltenham lesson I learned – don't expect anything."

RW: "Douvan, to us, was the best horse in the Supreme. Un De Sceaux had the best form in the Arkle. Faugheen, I thought his form was rock solid after the Christmas Hurdle, so I went for him ahead of Hurricane Fly. And I thought Annie Power was unquestionably the best mare around."

HO'C: "This is the effect of Willie Mullins. His superiority in terms of the horses he has is incredible, and the fact that two nations went after that four-timer is a testament to the unbelievable trainer that Willie is. It wasn't like this was just Irish people backing Irish horses. This was so widespread. I was coming across people who had never heard of Kauto Star and they were still jumping on this accumulator."

RW: "If this was Thurles on a Thursday, you would fancy your chances of riding a four-timer. But this is Cheltenham, so you don't. When you've been going there year after year you know that no matter how well things are going, there always seems to be a shagging disappointment somewhere along the way."

HO'C: "There was a guy working in our office who was worrying about the fourfold from a long way out. He said it was going to be big, and it could be a real problem. And I kept telling him, 'Look, just getting those four horses to Cheltenham will be a massive achievement'."

PM: "That was what was so extraordinary about last year. Everything went right. We got no injuries in the run-up like we have this year with Faugheen and Arctic Fire. We were very conscious that everything had gone so right. We were waiting on something to go wrong."

“You don’t get to bask in glory or wallow in despair”

RW: "The place is alive for the Supreme. It's like the first five minutes of any big football game or a big soccer game. The place is rocking. Everyone's dreams are still alive. It doesn't matter whether you're a jockey, a trainer, an owner or a punter. For those five minutes before the first race starts, your opinion is still right and your week is still full of potential. That's what makes winning the Supreme that bit different."

PM: "Dad made no secret what he thought of Douvan. We were all very excited to see was he as good as we thought he was. Could he walk the walk? And he did."

RW: "There's never any huge team talk with Willie. We don't go into the tactical battle or anything like that. But he did say at one point, 'Look, something will go wrong somewhere along the way. It's bound to. What we do is we keep moving forward, good or bad.' So when Douvan won, it was great and you enjoy the moment. But at Cheltenham you don't get to bask in glory or wallow in despair. The next race is with you before you know it. You're a professional. You have to move on."

PM: "Un De Sceaux was a heart-in-your-mouth job. Was he going to run away altogether? Was he going to fall? He made a mistake at the first and you were thinking, 'aw Christ, this is only going to go one way now.' So he was exciting to watch, in more than one way."

RW: "I had it in my head from maybe a month out what I was going to do in the Champion Hurdle. From the first scratchings, it was clear that there was no front-runner in the race so I knew that I was going to make the running. And we went out and Faugheen did it. He missed the second last but quickened up really well, jumped the last well and sprinted away. Brilliant."

PM: "The Champion Hurdle was an odd race for me personally. Obviously it was great to see Faugheen winning but I was cheering on Hurricane Fly. Much as I got a kick out of Faugheen winning and Danny [Mullins, cousin of] coming second on Arctic Fire, I was watching it without really knowing how to feel about it. Hurricane Fly is Hurricane Fly."

HO'C: "I was working in the press room and it just went wild in there, especially after Faugheen won because Annie Power was basically a foregone conclusion."

“Annie Power at the last fli . . . is down!”

RW: "Weighed in, weighed out for Annie Power, had a quick chat with Willie. There was a bit of pace in the race so we were confident enough that one or two of them would go on and there'd be a decent gallop. So that's what we said, park it fourth or fifth down the inner, happy days. Everything was rosy.

PM: "At the start of the day if you'd said which of them was the most likely, no doubt about it – you'd have said Annie Power."

HO'C: "Every journalist in the place only wanted to talk to us about how much money we were set to lose. They wanted to file their copy and get it sent even before the mare's race started because it was the story of the day, how much the punters had won. You could see them writing it up and just waiting to fill in the blanks once she came up the hill."

RW: "And then she fell."

Racecourse Commentator: "And as they come into the home straight, the four-timer is on. Annie Power and Ruby Walsh, showing in front. But Glen's Melody, her stablemate, is the danger as they approach the last flight. Bitofapuzzle is behind them in third position. Annie Power at the last fli... IS DOWN!! Annie Power has gone when in front at the last!"

PM: "I always go down to the end of the chute to watch the races, just after the last hurdle. That's where the stable staff go. You tack up the horses and give the jockeys a leg up and then you follow them down the chute. We had ringside seats for everything, including Annie's fall."

HO'C: "I'll never forget it. There was 20 seconds of nearly absolute silence in Cheltenham. Nobody could actually say anything. They couldn't speak. It was like, 'did that really happen?'"

RW: "She just jumped it from too far back. There was a whole extra stride there for her. She could have taken one more full stride and it would have taken her just in front of the hurdle. It would have been tight but not too tight. But she just let fly from too far back.

PM: "We were riding the crest of a wave. We were confident before the day started and sure then when the day had gone so well already and she hit the front and went five lengths clear, you were just thinking, 'God, this is some day.' And then bang, she's on the ground."

RW: "I can't explain why. Everyone has their own opinion, but I can't tell why she did it. Even her trajectory counted against her. If she'd got up, she might have got there. It would have been untidy but she could have had time to get her feet out in front of her. But she didn't. She went low and down. Even as she hit the top bar of the hurdle, I was thinking that she might make it, she might get a leg out. But by that stage, it was already done. When she didn't land on her front feet, that was it. She landed with her hooves tucked and that meant curtains. Goodnight."

PM: "It was an awful fall. It happened in front of me. She could have broken her neck because of the speed she was doing."

Fiona McStay, owner of Glen's Melody: "I was down at the rail, just in front of the final hurdle. And I was watching Annie Power, like everybody else. I was hoping and praying she got up. I took my eye off Glen's Melody and it was sort of bittersweet at that moment because you wouldn't want to win it in the case of a fatality. It would have been a disaster for everybody."

RW: "When I was going out over her ears, I could see her head was folding in under her. And when you see that, you only have one thought. 'Oh God, don't break your neck.' I rolled and I could see her behind me. When I got onto my knees, I was looking directly at her. By then, she was starting to get up so when you see that, you know she's 100 per cent."

PM: "I was looking at her to see if she got up. Then when she did get up, I was looking to see where Glen's Melody finished. Talk about a rollercoaster of emotions inside 15 seconds."

FMcS: "When she got up, it was a blessing. And I could turn my attention then to Glen's Melody. We didn't know if she won because it was so close on the line between her and Polly Peachum. We stood waiting on the photo, which was nerve-wracking to say the least. It was only a couple of minutes but it seemed like an hour."

PM: "Even the thing that went wrong – Annie falling – ended up going right because (a) she got up, and (b) Glen's Melody won and saved the day. The strongest emotion I remember from the day is relief that she got up."

“It was like crashing a car but being kind of okay afterwards”

Bookies lie. They over-egg and they undersell, depending on the situation. The next day’s papers were full of figures handed down by the betting industry’s PR people to quantify what Annie Power’s fall had saved them. Everything from £40 million to £100 million was thrown around. One press release pronounced it: “The most expensive bullet the betting industry ever dodged.”

In an effort to nail jelly to a wall, the Irish Times asked an industry insider, on condition of anonymity.

II: "I can tell you within five million what it is because I went out of my way to ring people in different firms who I knew last year to find out what it was, for my own curiosity. It's 5 million either side of €40 million. And I would say that with some degree of certainty. Somewhere in the €35 million to €45 million range. Being honest, I thought it would have been more. I remember at the time, just in my phonebook, I knew lads that had it for a quarter of a million, 50 grand, those kind of figures. I was a bit surprised at the number I heard – I thought it would be more. But I had no reason not to believe it either. This wasn't PR stuff, this was from people in the firms who would have no reason to talk it up or down."

HO'C: "We don't release figures as a general principle. Whatever she saved us, it was still quite a bad day. It was like crashing a car but being kind of okay afterwards. You have that gasp and you go, 'This is bad.' But then there's that bit of relief. You're thankful but you're not delighted because you realise how close you sailed to the wind."

RW: "You can't dwell on it. I had Nicholls Canyon on the Wednesday, I had whatever else I was going to be riding. You can't be sitting thinking about Annie Power for hours. It's like a guy missing a penalty – you have to move on. It's history. It was my chance to ride a four-timer in Cheltenham and it was gone."

PM: "To me the whole day was an anomaly. I can't imagine we'd ever have a day again where everything went right to that extent."

RW: "That's life. I was and still am grateful to have ridden a treble and to have won the Champion Hurdle on Faugheen. She was the icing on the cake. But I still got the cake. Actually, she wasn't even the icing on the cake. She was the cherry on the icing. To get to ride three winners in one day at Cheltenham is the icing on the cake. She would have been the cherry on top."

HO'C: "In January 2015, people were backing the four-fold at 43/1. This year in January the fourfold in the same races was only available at 9/1 or at a push 10/1. So the one thing you can say for certain is that Annie falling last year didn't put people off trying their luck at it again this year. It was a life-saver on a bad day. That was a bad day for bookies anyway, but this saved it from being a disaster."