I asked important EU and UK people involved in Brexit talks what they made of Boris Johnson's claim on BBC that:
1: the EU would be prepared to cancel Northern Ireland backstop.
2: continue free and frictionless trade with UK for an "implementation period" after Brexit on 31 October.
3: negotiate a new package of measures to keep open border on island of Ireland during the implementation period, and
4: would break all their own red lines because they won't like Nigel Farage's 29 MEP's turning up at the European Parliament and will panic when Johnson says he won't necessarily pay all the £39bn Theresa May agreed UK owes EU in full or on time.
This is what one influential EU figure said: "I hear a herd of unicorns trampling around."
And another said "preposterous rubbish".
I can already hear Johnson saying: "They would say that, wouldn't they?"
But if he becomes PM he will need all his persuasive charm to avert a no-deal Brexit.
And to be clear, EU leaders won't be terrified of that outcome, because they understand parliamentary arithmetic as well as you and me, and they will assume MPs would trigger a general election rather than roll over and allow the UK to leave the EU without an agreement.
Tory members who will decide the outcome of the leadership contest cannot be confident that Johnson can break the Brexit deadlock.
If they back Johnson, they are voting to be cheered up by an optimist.
And that may be understandable, even rational in these dark times.
But in the wee hours of the morning, some of them may fear he's the cabaret act on the Titanic.