Fantasy island: Tim Walker looks forward to one last helping of Lost

On the evening of 22 September 2004, Lost exploded into the viewing schedules of unsuspecting television audiences like a jetliner crash-landing on an empty beach. That opening scene, in which 48 survivors escaped the flaming wreckage of said plane on said beach, has never really been surpassed in the five series since. But if, like me, you were sucked into the show's Lord of the Flies-on-acid intricacies, you'll find it bittersweet to think that the invulnerable smoke monsters, the involuntary time travel and the interminable Jack/Kate/Sawyer love triangle are finally coming to an end, with the show's sixth and final season beginning next Friday night.

I love Lost the way I love fast food. I look forward to it with a sugary pang of guilt, devour it lustily and then, an hour later, find myself hollow, disappointed and regretting my former enthusiasm. Yet I keep going back for more. Executive producer Damon Lindelof recently said of the show's forthcoming climax: "There is certainly a hope that everybody universally loves the ending, but I don't think it would be Lost if there wasn't an ongoing and active debate... If I could put on my predicting hat, there's going to be some that think it's the worst ending in the history of TV."

If I might translate for a second, I would suggest that what Lindelof is trying to say is: "We had no idea how to wrap this thing up. It's going to be loopy and unnecessarily complicated, and there'll be a whole bunch of loose ends left flapping in its wake. It might be fun all the same. We can but hope." Lindelof and his co-creators always claimed to have conceived the show's ending early in its genesis, but anyone who's been trying to keep track of the last 103 episodes will find that somewhat hard to believe.

For one thing, the show's modus operandi is to make you believe it's just answered one of your many questions, only for you to later realise that all it was doing was posing a new question, such as: Are the crash survivors in purgatory? Why does the statue only have four toes? Why does Richard Alpert never age? Do they really have to keep pressing that damn button? What did Vincent the dog eat in the jungle? Who the hell is Jacob? And can Lost really provide satisfactory responses to all of these queries in the 18 hours (minus commercial breaks) that it has left?

The supernatural elements that make the show so baffling were not, in fact, part of the original concept. They came on board with J J Abrams, the writer-director who has almost singlehandedly revived the Saturday afternoon TV serial for the interweb generation – which doesn't watch his shows exclusively on Saturday afternoons, or on TV, but whenever and wherever it wants , via iTunes, The Pirate Bay or a Sky+ box. To round out his genre credentials, Abrams is also responsible for the spy show Alias and the sci-fi show Fringe, as well as last year's movie remake of the TV serial to end them all, Star Trek.

Like all of those series, Lost is high-class trash. It lacks the loftier qualities of Mad Men, The Wire or The Sopranos. Fans more committed than I may cite its frequent highbrow references to literature, science and philosophy. But its intellectual sheen has the whiff of Wikipedia, not of an actual library. And that's no bad thing: Lost was tailor-made for the obsessive conspiracy theorising of the internet, where the show has its own substantial community of bloggers and message board contributors. They decode the meanings of loaded and eerily familiar character names like Locke, Hume and Hawking; they debate the significance of the books those characters read; they teach each other numerology in the hope of deciphering the message in Hurley's lottery numbers (4, 8, 15, 16, 23, 42); they spot the Dharma logo on everything from tinned beans to live sharks.

The likes of Lostpedia.com are an invaluable resource for an average viewer like myself, who can't be expected to remember the precise significance of each brief cameo player from one series to the next. In the days before the internet, I suspect Lost would have haemorrhaged bewildered viewers far more quickly than it has. Yet in the US alone, it still boasts a weekly audience of more than 11 million. The conspiracy theorists among them will inevitably have concocted their own ideas of what the island is and why the characters are there; that's what conspiracy theorists do, after all. But the key to this final series is not to expect anything – or to expect very little. Then you can't be disappointed. Can you?

Series six of 'Lost' begins on Friday 5 February at 9pm on Sky1

Get Lost: A survivor's guide

Your chances of jumping smoothly into the narrative at this late stage are slim, so if you're a novice, best rush out and buy some DVD boxsets or brush up on Lostpedia.com. But rusty fans should buckle up for a compact chronological catch-up of the series' mindblowingly labyrinthine plot.

Series one

On a flight from Sydney to Los Angeles, Oceanic flight 815 crash-landed on a deserted Pacific island, leaving 48 survivors, including: handsome doctor Jack, sexy fugitive Kate, smouldering conman Sawyer, miraculously cured paraplegic Locke, former Iraqi torturer Sayid, heroin-addicted rock star Charlie, overweight lottery winner Hurley and a dog called Vincent. Jack and Kate looked like getting frisky on the beach where the survivors made their camp, but Kate was also attracted to the roguish Sawyer. In the meantime, the jungle started spewing forth smoke monsters and hungry polar bears. Locke discovered a hatch in the ground somewhere in the jungle and spent most of the series trying vainly to open it.

Series two

Some survivors from the other half of the plane – which crashed across the island – trekked to the beach to find their fellow passengers, only to spend the rest of series two getting killed one by one. The "Others", the original inhabitants of the island who'd been snooping around killing and/or kidnapping survivors, lived in holiday chalets and were led by Ben, a budget version of Kevin Spacey doing "sinister". Locke blew the hatch open and found angry Scotsman Desmond down in the island's concrete catacombs, listening to records and pressing a button to prevent the destruction of the world (don't ask). Locke decided not to press the button. The world sort of ended – well, the sky went all white for a minute or two.

Series three

Desmond woke up seeing the future – specifically, that Charlie was going to die, and there was nothing he could do to stop it. Charlie died. Meanwhile, Jack, Kate and Sawyer were taken prisoner by the Others. Jack agreed to operate on Ben's cancerous kidney. Kate and Sawyer got freaky. Jack got friendly with Juliet, one of the Others, then helped Kate and Sawyer escape. Locke dumped his friends and started hanging out with the Others. Locke and Ben went to see a ghost called Jacob in a hut in the jungle. Then Ben shot Locke because he felt threatened by how chummy he was getting with the other Others. (Ben is deeply insecure.) A freighter arrived to take the survivors home. Or did it...?

Series four

Four sciencey people from the freighter landed on the island in a helicopter, but they were more interested in finding Ben than they were in saving the Oceanic survivors. And it turns out the sciencey people weren't the only ones on the freighter; there were also a band of mercenaries sent by the villainous Charles Widmore (Jim from 'Neighbours'), hell bent on killing everyone. But Sayid and the Others somehow kicked their asses anyway. Claire disappeared in the jungle. Like, literally disappeared. Locke took over leadership of the Others. Ben pulled an underground lever and moved the island. Like, literally moved it. The sky went all white again. Some of the survivors were in the helicopter when the island moved, so they crash-landed in the ocean, only to be rescued by Desmond's girlfriend, Penny, in her posh boat. Penny, incidentally, happens to be the daughter of Jim from 'Neighbours' – sorry, I mean "Charles Widmore".

Series five

Jack, Kate, Hurley, Sun, Sayid and Claire's baby returned to the mainland claiming they were the only survivors of the crash. Sayid became a hitman. Hurley became a nutjob. Jack became an alcoholic, then persuaded the rest of his reluctant friends to return to the island. On the island, things went mental. The characters kept involuntarily flashing through time, which gave some of them killer nosebleeds. Eventually, they were stuck in the 1970s, where they pretended to be part of the Dharma initiative. We met two guys who'd been on the island for a very long time. One wore white and was called Jacob. One wore black and wanted to kill Jacob. Ben and Locke killed Jacob instead. Faraday, one of the sciencey guys from the freighter, decided to detonate a hydrogen bomb and destroy all the magnetic energy that caused the plane crash in the first place, which would reset the clocks and put everyone back where they started, on that flight to LA. After a lot of shooting, grenade-throwing and so forth, the bomb fell down a hole, where Juliet banged it with a rock. The sky went all white. Again.

1. Will Kate end up with Jack or Sawyer, and could she make up her mind already, puh-leeze?

2. Which ones are actually the good guys, the Others or the others?

3. Will the survivors all end up dead, or will they all end up alive again (including the ones who died)?

4. Is Locke really Locke, or is he the Man in Black – and who is the Man in Black anyway?

5. What and where is the Temple?

6. How on Earth did Jim from Neighbours get so darned evil (and so darned rich)?