For the second year in a row, Lewis Hamilton heads to the Brazilian Grand Prix on the cusp of winning the Formula One world championship.
WHAT HAMILTON NEEDS TO DO
If Massa wins in Brazil, Hamilton must finish at least fifth to be champion
If Massa is second, Hamilton must finish at least seventh
If Massa is third or lower, Hamilton is champion regardless of his result in Brazil
If he succeeds, he will become the youngest ever F1 champion, an incredible achievement at the start of a career that seems destined to establish the 23-year-old Englishman as one of the greatest racing drivers in history - regardless of whether he leaves Sao Paulo with the title.
But while Hamilton holds what at first appears to be a comfortable seven-point advantage over Ferrari's Felipe Massa with only 10 available at the Interlagos circuit, there a number of reasons why his task may be harder than it looks.
FERRARI'S EXPECTED SPEED
Ferrari have been very strong in Brazil for the last two years and are widely expected to be so again - despite their strange lack of pace at the last race in China.
Massa won at Interlagos in 2006, and the Brazilian handed victory to team-mate Kimi Raikkonen last year to ensure he - rather than McLaren's Fernando Alonso - won the title.
Ferrari have been strong in Interlagos in the recent past
If that form continues, a Ferrari one-two in Brazil seems a certainty - which would leave Hamilton looking at a third-place finish at best.
That would still be more than enough for him to win the title - he only needs to finish fifth to ensure that even if Massa wins.
But it may be that Ferrari's actual pace in Brazil is not as strong as many expect.
They and McLaren have been extremely evenly matched this season - to the point where it is difficult to predict who will have an advantage at any given race.
Ferrari's pace in Brazil in 2006 was largely down to a super-tyre provided by Bridgestone, when most of their rivals were still on Michelins.
Last year, they were a lot quicker than Alonso in the race - but Hamilton was the quicker McLaren driver that weekend and his performance was compromised by having to fight back through the field after early problems.
And he set a fastest lap within a few hundredths of Raikkonen's, and faster than Massa's.
Nevertheless, the expected high temperatures could point to a slight advantage for the red cars because the Ferrari tends to keep its tyres in better condition for longer in those conditions.
HOW FAR WILL FERRARI GO?
Hamilton's strong points position reduces his vulnerability to Ferrari tactics.
In theory, Ferrari could use Raikkonen to "back up" Hamilton in a way that is advantageous for Massa.
That basically means that if the Finn got in front of the McLaren, he could drive deliberately slowly enough to mess up Hamilton's race.
Schumacher made life very difficult for Hakkinen in Malaysia in 1999
The team employed this tactic with great success in Malaysia in 1999 to ensure the title battle between Ferrari's Eddie Irvine and McLaren's Mika Hakkinen went to the last race.
Michael Schumacher rode shotgun for Irvine, gifting the Northern Irishman the win and making Hakkinen's race a total misery with some pretty dubious behaviour.
Whether Raikkonen would be prepared to go as far as Schumacher, however, is another matter.
For one thing, it is just not his style to drive unfairly. He's hard, but not unfair - which is not something you could say about Schumacher.
For another, it is debatable how much - deep down - he really wants Massa to be champion. Although if you are paid $50m (£30.7m) a year, your employer might expect you to swallow a few things you don't like.
At the same time, Massa will be aware that if Hamilton fails to finish in Brazil, his task gets easier.
Schumacher famously took Damon Hill out to win the title in 1994, and tried unsuccessfully to do the same to Jacques Villeneuve in 1997.
It is unlikely Massa would follow the German's lead - he and Hamilton have a reasonable relationship off the track, and it does not seem to be Massa's style.
All the same, it would be a good idea for Hamilton to avoid situations where he would be vulnerable to that sort of thing.
HAMILTON'S RED MIST
Mistakes under pressure cost Hamilton the title last year, and he has shown a similar vulnerability at times this season.
Can Hamilton keep his emotions under control this time around?
He was off-form early in the season, admitting later that the pressure had got to him.
And he made a mess of the Japanese Grand Prix three weeks ago when, after a poor start, he misjudged his braking for the first corner trying to prevent Raikkonen taking the lead.
He drove a flawless race in China a week later, but questions linger over his temperament when the stakes are at their highest.
THE PROBLEM OF HAMILTON'S UNPOPULARITY
It is an open secret that Hamilton is not hugely popular among his fellow Formula One drivers.
Part of that is undoubtedly to do with his success and talent - as our columnist Mark Webber put it last week, "people inevitably get jealous".
But the other drivers' beef with Hamilton goes beyond that.
It is also to do with how he carries himself. Several of his rivals have detected more than a hint of arrogance about Hamilton in the way he views them and himself.
That explains why so few have been willing to defend him when he has got into trouble in recent weeks - most notably following his penalties in Belgium and China.
This is a potential concern for Hamilton.
It is not that anyone would deliberately take Hamilton out, but nor are many of the drivers going to feel well disposed to making his life easy in Brazil.
SLIPPERY WHEN WET
Sao Paulo is in the tropics and rain is always a threat at the Brazilian Grand Prix, even if the race has only been wet twice in the last 10 years.
In theory, a wet race should play into Hamilton's hands. The McLaren is a better car than the Ferrari in the wet, and Hamilton is the best wet-weather driver in the sport.
Even the best drivers can be caught out in the wet at Interlagos
But rain also introduces a random element that Hamilton could do without.
Firstly, there is the heightened risk of making a mistake. When it rains at Interlagos, it really means it. Over the years, this has caught out even the best wet-weather drivers - Michael Schumacher spun off in the 2003 race, for example.
Hamilton drove brilliantly to win in the wet at both Monaco and Silverstone this year, but in both races he got away with making mistakes on the way.
Equally, wet races are not always wet all the way through, and the off-the-cuff strategic decisions often required in mixed wet-dry races have caught McLaren out in the past.
The most striking example was in China last year, when Hamilton stayed out too long on worn-out tyres trying to win a race he did not need to win, and ended up sliding off the track and into retirement when he should have been tying up the title.
Interlagos is not everyone's favourite circuit. It is scruffy, working conditions for the teams are cramped and the huge, sprawling city of Sao Paulo has a distinct edge to it.
But the atmosphere is inevitably brilliant. And this year, with a Brazilian competing for the world title, it will be electric.
Interlagos is a hot, muggy, cauldron for a world title showdown
As Damon Hill puts it: "It's a great place to finish the world championship. At least it's a country that really gets Formula One and is passionate about it. It'll be stupendous."
The crowd is full of vitality, but the track itself also plays a part in generating this ambience.
It is in a bowl - so large parts of it can be viewed at once. The lap is short and eventful, and the races it produces are often fast and frenetic.
And it has one of the most awkward first corners in F1. Cars brakes from 200mph at the end of a long, long straight, and then plunge downhill as they turn into a tight left-right chicane.
It is a great overtaking spot, but it is also notorious for producing first-lap crashes - Hamilton will have to be careful not to get tangled up in an accident, whether of his own making or someone else's.
OUT OF HIS HANDS
No matter how careful Hamilton is, he cannot control the reliability of his car.
A gearbox glitch cost Hamilton the title in Brazil last year, when his car slipped out of gear, and he was at the back of the field before it got going again.
Rumours that the problem was caused by Hamilton himself pressing the wrong buttons in the cockpit will not go away but, whatever the cause, it underlines how easily such problems can arise.
McLaren's reliability has been stunning throughout 2008 - Hamilton has had not a single mechanical-related retirement and team-mate Heikki Kovalainen's engine failure in Japan was Mercedes's first since 2006.
That is an impressive record, which should give Hamilton peace of mind heading into Brazil.
But the failure on Kovalainen's car in Japan came a race after he had to play his one "joker" for a free engine change in Singapore - and led to speculation that the Mercedes V8s might be running closer to the edge than it appeared.
While Hamilton has not needed to invoke his free engine change yet, now it is the final race he is not allowed to. So any failure before the race would mean a 10-place grid penalty.
On top of that, F1 equipment is under such extreme strain that reliability can never be taken for granted - and, with F1 engines being required to last for two races, Hamilton's engine is on the second race of its two-race cycle.
It would be sod's law if, after such a solid year, Hamilton's McLaren was to have its first mechanical failure in the most important race of all.