Melbourne Cup countdown: It hasn't been as if horse racing needed all the melodrama to command media attention here in Australia. The sport dominates the sports pages, arguably to an extent unequalled elsewhere in the world. The state of Victoria is preparing for the high point of its spring festival, next week's Melbourne Cup on the first Tuesday in November.

Already the great race is torn between two riveting narratives, the will-she-won't-she question of whether the country's greatest horse of modern times will attempt an historic three-in-a-row, and the seemingly endless series of Agatha Christie mishaps befalling declared competitors.

This latter strand began after the mighty Godolphin stables folded their tents a few weeks ago when top shot Fight Your Corner tore a tendon and, in the gloomy aftermath, it was decided to withdraw the other runners.

In the time since there's been further misfortune, with the on-off saga of Plastered and, this week, the spectacular end of English raider Carte Diamond's bid in a calamity on the gallops two days ago.

Having been entered, withdrawn, re-entered and nearly sold in the past few weeks, Plastered was found on veterinary inspection to have respiratory problems and was quickly out of the Melbourne Cup and back with his owner.

Brian Ellison, trainer of Carte Diamond, came over from England, only for jockey Weichong Marwing to get thrown and the horse to career into a temporary running rail. Having somersaulted into a tangle with the twisted aluminium, the bleeding contender was led away by Ellison's daughter Lorraine - herself the survivor of a car crash earlier in the week - who could only bring herself to utter one word: "Gone."

The more up-beat story concerns Makybe Diva, the nation's favourite horse. Having won the last two Melbourne Cups, she stormed to victory in the Cox Plate last weekend, thus cuing a week of frenzied speculation about whether she'll go for three-in-a-row at Flemington next Tuesday.

No horse has won the Cup more than twice.

Owner Tony Santic, a millionaire, Port Lincoln tuna fisherman with a bleached mullet hair-do visible from space, is thought to be in favour of the run, whereas trainer Lee Freedman has been more cautious. After weeks successfully targeting the 2,040-metre Cox Plate, the seven-year-old mare would be carrying 58kg over 3,200 metres.

It's an improbable task for most realists - the horse has never carried that weight to victory in three attempts - but the Diva's massive popular and romantic appeal has long since outstripped the demands of hard-nosed assessment. Last weekend's win made the horse Australia's greatest prize-money winner on the track with $11,426,685, taking her beyond Sunline.

Makybe Diva has gone, in the words of one observer, "from a 3,000-metre slugger to a middle-distance champion".

Favourite for last Saturday's Cox Plate, the horse was still attracting some scepticism, having been seen blowing hard and sweating in training only a couple of days before the race and with jockey Glen Boss going through a lean spell.

There were some frowns that Diva's likely challengers tried to break her half-way around the track, a long-shot strategy to deal with a proven stayer, but she responded magnificently to record an emphatic win in a field leading bookie Mark Read described as having "more depth and quality than any Cox Plate I've seen in the last 10 years".

So the scene is set for Tuesday, except that for all the mare's favouritism, a status she'd enjoy at this stage with three legs, questions remain about the feasibility of pulling off the unprecedented hat-trick after a season spent targeting the middle-distance Cox Plate.

It's 30 years since Think Big carried 58kg to victory, and whereas the doyen of Australian trainers, Bart Cummings, believes the weight is too little for the Diva, Boss said that his mount was spent last Saturday.

"The fuel gauge was empty," he said after the race in Moonee Valley. "She pulled up better after her two Melbourne Cups."

For trainer Freedman it's a conundrum at the end of an exhausting fortnight that started with his having to destroy his much-loved Mummify, who broke down after a brave third place in the Caulfield Cup.

He celebrated Makybe Diva's great victory a week later, but is perceptibly jumpy about what decision to take now.

Beckoning is greatness beyond the usual cliched parameters of the description, and comparison with Australia's legendary Phar Lap, a hugely popular Depression-era horse - a sort of Antipodean Seabiscuit.

The public see no harm in giving it a lash, but Freedman's caution is understandable.

In the midst of all this, Irish challenger Vinnie Roe, a decent second to the Diva 12 months ago, is attracting a good bit of attention given the general attrition rate and the question mark over the mare.