Mark Reckless defection: Will more Tory MPs join UKIP?
Mark Reckless began with an apology.
"Sorry I didn't get back to you," he told me when I interviewed him after he announced his defection to the UKIP.
The night before he abandoned the Conservative Party - choosing to announce the news at the world at the UKIP conference - I had texted him asking about rumours that he was off.
There was no reply.
Inevitably, plenty of other journalists will now be contacting plenty of other MPs to ask the same question.
Carefully crafted messages at the Conservative conference will go ignored by hacks trying to find the next rebel.
Pledges of loyalty will be sought, received and not always believed.
With three by-elections now in play, this could go on for some time.
Ukip purple or Tory blue
Was Reckless's move a surprise? Up to a point.
The last defector, Douglas Carswell, had been seen chatting with him during Tory rebellions past.
But victory won't come easy for UKIP in Rochester and Strood, when Mark Reckless - winner with a 9,953 Conservative majority last time out - attempts to win re-election with a different party.
And an optimistic Conservative might see an opportunity here.
A Reckless defeat would cool the heels of Tories tempted to rush to UKIP, for a while at least.
Political careers can end in Nigel Farage's company just as surely as they can in David Cameron's.
Should Reckless win though, Conservatives will wonder whether they are more likely to survive in politics in UKIP purple than Tory blue.
Some may keep quiet in the short term.
The precedent set by both Carswell and Reckless means if they want to defect, they have to go to the voters.
Those uncertain whether their voters would want them back will think twice.
As the general election nears though, caution may be thrown to the wind.
For Tory MPs with little hope of promotion, and every chance of losing their seats, UKIP is a tempting lure.
Farage hopes it would prove just as attractive to a Labour MP.
If he got his way, Westminster's favourite guessing could become even more intriguing.