Blimey, that was a disorientating phone call.
Chatting to a credible source -- a former special adviser from the heart of New Labour -- about the Miliband brothers for a feature in this week's magazine, I turned to the contest more broadly. And, to my astonishment, this source made the case for why Diane Abbott may well win and become the next Labour leader.
How? The key is in the second preferences of those who vote for the candidates who come last overall from the three electoral colleges of MPs and MEPs, unions and affiliates.
The starting point for my source's theory, however, is that Abbott is will do "much better" than expected. He says the polls do not matter because of the second-preference factor, and argues that the hustings matter little because most of the 100,000-plus members will not attend any of them.
As such, conventional Westminster wisdom about who is up and who is down in the race can be discarded for the most part. Instead, members will watch Newsnight tonight, as Richard Darlington has pointed out on this blog, and they will read the Guardian, Independent and New Statesman. Abbott, of course, is a strong media performer.
The source, who knows the Labour Party as well as any adviser, predicts that overall, in first preferences, the top three will be the Miliband brothers and Diane Abbott, and that Ed Balls and Andy Burnham's second preferences will transfer first, because they will make up the bottom two.
The question then is whom those who vote for these two will offer as their second preference. Here (forgive me) we are stepping even further into the darkness. But we can look at last year's deputy leadership campaign, in which Harriet Harman emerged ahead of the favourite, Alan Johnson, after the second preferences of votes for Hazel Blears, Peter Hain, Hilary Benn and -- decisively -- Jon Cruddas pushed her over the line.
This may be pushing it, but my source believes there are reasons why a good proportion of those who voted for Balls and Burnham will have Abbott as their second preference, while those who did not vote for a Miliband are unlikely to do so as second preference. Balls may attract similar votes from the "traditional left", while Burnham supporters, taken in by his northern, anti-establishment campaign, may also like the other perceived anti-establishment candidate, Abbott.
So, will Diane Abbott be the Harriet Harman of 2010? In reality, almost certainly not. But do not underestimate the unpredictability of this contest.