It's been nine months since the referendum, but today Theresa May is finally starting the UK on its journey out of the EU.
If you're unsure what follows, let Huff Post UK guide you through what happens next as the UK jumps off a cliff/escapes into freedom (delete as per your view).
I've heard a lot about this Article 50 – what is it, and why should I care?Article 50 is part of the Lisbon Treaty, which is basically the rules for how the EU operates.
It sets out the how an EU member can leave the organisation, and it's pretty simple: tell Brussels you want to leave, and you have two years to get out.
The two-year time period can be extended, but only if every other member of the EU agrees.
So today, Theresa May is telling the EU that we're off?
Precisely. Last night the Prime Minister signed the letter saying the UK was leaving, and on Wednesday at 12.30pm it will be handed to European Council President Donald Tusk in Brussels.
And that's it. Start the clock.
What happens next? Surely the UK just clears its desk in Brussels and gets the Eurostar back to London?
The UK and EU now have two years to hammer out a leaving settlement, including how much money Britain owes for bailing out. The EU want a cheque for £60billion to cover projects they've already agreed to fund, other spending and pensions.
There are some in the UK who think we shouldn't pay any money, but that approach might harm our chances of getting a shiny new trade deal...but we'll come back to that.
OK, so once Tusk has the letter, what do the rest of the EU do? Burst into tears?
Perhaps...but I doubt it.
Tusk has said he will send out the draft negotiating guidelines to the remaining 27 countries within 48 hours, and then they will all get together on April 29 for a Brexit summit.
But don't expect this to be a sign that negotiations are moving forward quickly, as talks will be put on hold until the winner of the French election is announced on May 7.
It's unlikely talks will really begin in earnest until the Autumn, as the Germans also have elections this year, in September.
Even with a few months of not much happening, it surely won't be that difficult to sort out how much money we're going to pay the EU? This will all be done within two years, no problem.
If it was just settling the bill, you might be right, but alongside that negotiation a new trade deal is needed.
The EU don't want to talk about this until the divorce settlement is sorted, but Theresa May wants the negotiations to run simultaneously.
That's where the real drama will lie, as the UK tries to get the best possible access to the Single Market without being members. Getting that done within two years is a very ambitious task, especially as any trade deal needs to be voted on by parliaments in each of the 27 countries.
Including the UK, right?
The choice is deal or no deal.
Doesn't Theresa May want no deal?
I wouldn't go that far, but she's certainly made it plain that she will walk away from talks if the EU are trying to pull a fast one.
And no deal is...bad?
It would mean the UK trading on World Trade Organisation (WTO) rules with the EU, which will see tariffs placed on a range of goods, such as a 10% tariff on cars, 20% on alcohol and 35% on dairy products.
Some believe WTO rules aren't that bad, and the UK could thrive. In a couple of years, their theory might be put to the test.
That does sound like a lot to negotiate in two years. What if time runs out?
If the clock strikes midnight on March 29 2019 and there is no trade deal, the UK will be out on WTO rules.
However, the EU could decide to extend the negotiating period, if all 27 countries back the move.
So in two years time we might still be in the EU?
Absolutely. There is no limit on the length of the extension, so negotiations could continue for years and years. Also, the UK and EU could sign up to transitionary deal, which keeps Britain in some parts of the union, such as the Single Market or Customs Union for many years to come.
Nigel Farage wouldn't like that would he?No. No, he would not.