With just three amateurs left in the competition, it will be a knock-em-down, drag-em-out battle for the two places in the grand finale. Who will find themselves stumbling at the second-last hurdle? Will it be loveable-yet-determined Jessica, determined-yet-loveable Georgia, or Billie, who is determined to be loved?

We begin with George proclaiming that she is making good decisions, and it's about time. Meanwhile Billie does her hair, which is important given how much of it is going to end up in her dish.

At the kitchen, the three ladies are welcomed by a round of applause from the balcony, all the eliminated contestants having arrived to shout unhelpful advice and provide general distraction from the job at hand. Matt says the judges are "exceedingly proud" of the three finalists, which is pretty arrogant of the judges – they didn't do it.

Each amateur is about to provide a main and a dessert for twenty guests plus the judges. They have to make the whole thing by themselves, not counting the advice from the balcony.

During the challenge Shannon Bennett will be wandering around pestering everyone as usual. "For one of you, it all ends here," says George in an extremely threatening manner.

Cooking begins. Immediately Georgia signals her commitment to a bold strategy of "knowing what I'm doing". Jessica, who has no interest in this, runs straight into the pantry to gather ingredients for Japanese cuisine, which she has loved ever since she realised it matched her haircut.

We cut to an as-yet unidentified failed contestant on the balcony. She enthuses about the finalists. "You could not get three more different women," she says of the three twentysomething middle-class white women below.

Forty minutes in and Billie has her shanks in the pressure cooker, whatever that means. For dessert she is making a spider, in homage to the monster Shelob from Lord of the Rings, her culinary role model.

"One hour has passed. There are three hours left," shouts Shannon, fulfilling his duty as basic subtraction adviser to perfection. With only three hours left, Georgia is struggling to fillet her ocean trout – the decision to cook a bone-intensive meal is coming back to bite. As she screams foul curses against those ancestors who had the stupid idea of making fish a food, Shannon tells her to make her portion sizes larger, which is a pretty offensive bit of body-shaming.

Up on the balcony, Jessica's plan to make a cake out of popcorn doesn't sound right to Matthew, but bear in mind Matthew got eliminated so his views need to be treated with scepticism. As Jessica works on her bizarre popcorn Frankenstein cake, and Georgia has a slow trout-flavoured nervous breakdown, Billie is forging ahead with the terrifying, steely focus that has earned her the nickname "the David Boon of the kitchen".

Georgia has moved on to her dessert, a parfait that promises to be ironically named for people who speak French. She admits she's "really pushing it" with this dessert, which is a good strategy for anyone in a sudden-death elimination challenge who has already wasted a lot of time being very bad at the first bit of the meal.

Suddenly Billie's icy calm fractures as the art of wrapping shank meat in cling wrap proves beyond her. Billie can think of no other uses for shank meat – the balcony proving useless.

Meanwhile she's left her roast rhubarb in the oven too long, though whether it's possible to make rhubarb taste any worse is an open question.

Jessica has burnt her crumb, a painful injury at the best of times. She is worried because she believes the standard in this challenge is going to be extremely high, so she's got a major relief coming.

"You do not want to be the contestant going home!" Shannon cries, having suddenly had a personal epiphany and realising how this show works.

The nerves are getting to Georgia: as Masterchef fever takes hold of her fragile psyche, she has forgotten all about cooking and started obsessively spreading vomit across a piece of tracing paper. This could be a problem, as Shannon is screaming again and people are coming in through the front doors. "FIFTEEN MINUTES!!!!" Shannon shrieks.

"There is not a better table in Australia to eat at," Matt tells the newly arrived diners, "you'll have three of Australia's best amateur cooks cooking for you." The diners ponder whether having professional cooks cooking for them would beat it, but there is no time for contemplation, because the amateurs need to be plating up and Billie and Georgia are still disappointing Shannon with regard to how much meat they have. "Billie, are you happy?" he asks, which seems at best a loaded question.

Georgia is taking too long to plate up her main, and Shannon is getting all Gordon Ramsay in her face. It seems the only solution is to start throwing trout at the diners from the kitchen.

Finally we get around to the judges' tasting. They are strongly in favour of Billie's dish, because it is both spectacular and reminiscent of simple country girls. There is a moment of tension as they chew, and then suddenly a cymbal clash and you know it tastes good. "What a clever girl," says Gary, a black belt in patronising remarks.

Meanwhile Georgia's customers are watching their stomachs bloat, and Shannon is causing a lot of trouble for the editor who has to cut out all his swearwords. Georgia then makes a tactical blunder, falling even further behind by stopping the plating and talking about her food journey. Rookie mistake.

Jessica's pork belly – her food, I mean – is served to the judges. "Look at that pork!" Matt cries, in case nobody was. The pork doesn't really matter much though, as Georgia shows no sign of being able to actually get a plate to the judges.

Billie and Jessica have started their desserts while Georgia continues to mull over the nature of linear time. She may have to bite the bullet, serve up some empty plates, and hope her clean, minimalist presentation gets her over the line.

Miraculously, some food manages to make its way from Georgia to the judges' table. The tension is so high that the background synthesiser is having an embolism. Then BOOM! The big emotional piano chords chime in and it's clear that the house band loves Georgia's trout.

Dessert time, and as Billie pours fizzy drink over her ice cream the balcony bursts into rapturous applause because frankly they have led sheltered lives. Billie loves her spiders. "I love the theatre of it," she says, having taken notes on the way Masterchef judges talk.

Apparently the spider takes you back to a childhood memory, but you know what, George – some of us never had spiders as children and we would appreciate it if you quit flaunting your spider privilege. On the other hand Gary thinks the spider provides an "r-rated, adults-only experience", which I assume means he wishes to make love to a spider.

Jessica's turn. "If you'd shown me a photo of this dessert three months ago and told me it was mine, I'd have laughed at you," she muses, confident that even three months ago she would be able to remember whether she'd made a dessert or not. The judges say Jessica's dessert is good, so we know they're lying. Matt questions whether white chocolate, popcorn and grapefruit go together, and it's a crying shame our society has reached the point where a man needs to ask himself this question.

It's Georgia's turn to serve dessert, and it is not a raging success. Matt thinks you can see the pressure on the plate, which is easy to say when you've already seen it on the chef's face. Gary the human magpie wants it to be shinier. And yet…and yet…it's George's favourite dessert. Has the world gone mad?

Shannon says the three women have managed "high restaurant calibre standard", which is high chef food praising. Gary says their dishes are the best food they've ever eaten on Masterchef, trying to deliberately hurt past contestants' feelings. George then talks for about twenty minutes straight about something or other. The upshot is Billie is going through to the grand finale. But who will join her? "Going home's not an option today," says Jessica: a gross misunderstanding of the process.

Matt certainly doesn't misunderstand anything. "It comes down to the food you cooked today," he says, with all the wisdom that decades of eating brings. About half an hour later, he gets to the point: Georgia is in the grand finale and Jessica has learnt a powerful lesson about the advisability of popcorn cakes.

So, looking ahead to Monday's finale, who will come out on top? Will Georgia's ability to cry on cue and say extremely melodramatic phrases about what is, after all, just food, see her take out the trophy? There is a trophy, right? Or will Billie's deadly determination, unbreakable will, and tendency to dip her ponytail in everything she cooks be what impresses the judges?

It's too close to call, but we know that there'll be spectacular dishes plated up, we know that Heston Blumenthal is going to show up to ask Billie and Georgia to make a gold-plated asparagus pavlova, or a hamburger that looks like the Taj Mahal or some damn thing, and we know that it will run for at least seven hours.

For a live blog of Monday night's Masterchef finale go to smh.com.au or theage.com.au from 7.30pm.