One of the quotes which immortalised Conan Doyle's Sherlock Holmes was his aphorism, phrased as a question: "When you have eliminated the impossible, whatever remains, however improbable, must be the truth".

This is a principle I've used professionally many times, solving food poisoning outbreaks, the cause of which eluded the authorities. It is the process of eliminating the impossible that so often leads to the truth.

And it was exactly that technique which brought us in Flexcit to the Efta/EEA option as a mechanism for leaving the EU. Basically, there are only three broad stratagems available: the unilateral or "WTO option", the bilateral or "bespoke free trade agreement", or the multilateral half-way house of the EEA which keeps us in the Single Market.

By any measure, the "WTO option" – the original "hard" Brexit – is insane. In a balanced, sensible world, we would not even have wasted any time on it. But that hasn't stopped a lot of very stupid people advocating it, and the media giving them time and space to air their stupidity.

Equally, the "bespoke free trade agreement" is not realistic. All recent evidence screams out the obvious – that it is simply not possible to negotiate a comprehensive trade deal with the space of two years initially allowed by Article 50.

Having thus ruled out the impossible, we are drawn inexorably to the Efta/EEA option – not because it is the best, or even desirable. Simply, it is the only option available that gets us out of the EU in reasonable order, without wrecking the economy.

Since this is not a sustainable option for the longer-term, we are thus led to the view that Efta/EEA should be an interim option, pending development of solution for the long-term, which is more to our liking. And that, as Mr Homes would have said, is: "Elementary, my dear Watson!"

Despite this, though, there is a new breed of Muppets coming along, which has thoroughly confused itself about the nature of the Customs Union, mistaking it for customs cooperation – the nature of which is written into the EEA agreement.

Largely, this is why I have stopped reviewing their work. It does not matter what facts one adduces, or how clearly the arguments are expressed, these people are wedded to their own stupidity and are not going to release themselves from it just because they have got it completely wrong.

It was Shakespeare, however, who gave us the phrase: "Misery acquaints a man with strange bedfellows" but reality, it seems, has much the same effect. Thus does Booker observe in his column that the great Brexit riddle is throwing up some bizarre alliances.

On one side, we see Jeremy Corbyn and the SNP lining up with the City of London and the CBI, all insisting that we must remain in the European single market.

On the other, we see the hard-line Tory "Brexiteers" still calling for completely unworkable alternatives, such as a one-off trade deal which would take far too long to negotiate, or reliance just on "WTO rules" which, by exposing us to "non-tariff barriers", could shut us out of that market altogether.

And although Booker notes that Theresa May is under fire for not telling us which side she is on, "up to a point she could not have made her position clearer".

Three times last week in the House of Commons, she told Mr Corbyn, she said that she wants "the best possible arrangement for trade with and operation within the European single market, for business in goods and services".

The use of the word "within" is the give-away. You can either be in the Single Market, or you can be out of it. But the only way you can be in it and not in the EU is to remain a contracting party to the EEA Agreement.

Mrs May has not yet told us precisely how she hopes to achieve this, and there are variations on the theme. It may be that, by arranging for Efta membership to take effect immediately on our leaving the EU, we can remain parties to EEA Agreement without having to re-apply.

And then it is not beyond the bounds of possibility that the UK is able to negotiate changes to the EEA Agreement, which will allow the UK to participate on leaving the EU, without having to re-join Efta.

Exactly what Mrs May's intentions are we have no means of knowing, and she may continue teasing us a little longer, until she invokes Article 50. Booker nevertheless hopes she must by now have discovered – as did we - that any alternatives are just crazy wishful thinking.

Certainly, she has already ruled out the "WTO option" version of a "hard Brexit", leaving the pundits to invent new and ever-more mystical versions, without them ever taking the time out to define exactly what they mean. And the reality is that a brand new trade agreement with the EU is not going to satisfy the needs of the UK.

Perhaps the only real surprise to come is the choice of words that Mrs May will use to define her "British option", which will be a modified EEA arrangement, tailored to the UK's specific needs. And, as the Bard once said, a rose by any other name would smell as sweet.