Brexit: What if... Boris Johnson actually agrees a deal with the EU?

Get out your diary! If you are as much of a nerd as me.

Watching the two sides in Parliament tear each other to shreds this afternoon, it seems impossible to imagine them ever, ever, agreeing anything again.

The noisiest voices on both sides seem, at the moment, more interested in using every twist and turn to confirm their own views than hunting for a basis for resolving things together.

But let's for a second, contemplate that they can.

And imagine that Boris Johnson is willing to compromise, and manage to persuade his counterparts in the EU to budge enough too to allow him to strike an exit deal.

What would they do then?

Remember Boris Johnson's main priority is to stick to his Halloween deadline for Brexit.

But Parliament has changed the law to force him to ask for a delay if a deal hasn't been done and dusted by the end of the 19 October.

There is plenty of conventional wisdom around that says that's just not possible, given the EU summit where the deal may or may not be done is only on the 17th and 18th of next month.

While the mood music around the negotiations is better than a few weeks ago, the two sides are, in the words of one minister, "a million miles away".

But privately, sources sketch out this possible timetable. Ten days of intense negotiations ramping up as soon as the Conservative conference finishes next week (at the moment, it is expected to go ahead, even if Parliament continues to sit).

It might be wishful thinking, but if a deal is then done at the summit, the government would try to ram through Meaningful Vote Four, (remember that old phrase?) in a special Saturday sitting of the Commons on the 19th itself.

If the government were successful, then the process to request a delay might never be triggered, saving the prime minister the humiliation of having to ask for the delay he has claimed that he won't seek time and again.

Then the following 10 days would be spent in frantic efforts to get the legislation through before 31 October.

Insiders point out that even if the government misses the 19 October deadline, and has to write a letter to the EU to seek an extension - despite No 10 sabre rattling that they will find ways to avoid doing so - there is nothing that stops negotiations with Brussels continuing.

And there is nothing that stops the government trying to get a deal through the Commons after that point.

There are, though, lots of 'ifs' before we get to that place.