If Ali Abdulrahman al-Ghamdi really was the man who planned last month's suicide bombings in Riyadh, his surrender was about the most unique development in the history of Osama bin Laden's al-Qa'ida movement.
No fight to the death for MrGhamdi, no heroic last battle in the desert or the foothills of Afghanistan. He just turned up at the home of the Saudi Interior Minister's son after personally arranging - by telephone - to have a reception committee waiting for him.
"I thank God that my son handed himself in because this has comforted me and his family," Mr Ghamdi's father, Abdulrahman, told the Saudi daily Okaz. "This is the right thing to do - which he should have done earlier. We are not happy with these [suicide bombings] if he has really done them."
All of which begs a question: since when did al-Qa'ida members, dedicated to secrecy and self-immolation, surrender to the local constabulary? For if Mr Ghamdi really was involved in the suicide bombings, which killed 34 people, he will very soon have his head chopped off after morning prayers outside a neighbourhood mosque.
The Saudis congratulated themselves. Prince Nayef, the Interior Minister, confirmed that Mr Ghamdi had turned himself in, that his son had been involved in the surrender, and that the authorities would soon have other important members of al-Qa'ida.
No one doubts that Mr Ghamdi fought in Afghanistan and Chechnya - though, now 26, he could hardly have been involved in the Afghan war against the Russians. However, there is some doubt as to whether he really was with Bin Laden in al-Qa'ida's redoubt at Tora Bora before the Americans laid waste to the mountainsides in the autumn of 2001.
For the Saudis, however, any arrest can be displayed as further proof that the kingdom is joining President George Bush's "war on terror" and making amends - albeit a little late in the day - for the fact that 15 of the 19 killers of 11 September 2001 were Saudis.
"The noose has tightened," a Saudi official announced melodramatically. "There are checkpoints everywhere and suspects are being arrested all the time. He had no choice."
But is that true? Would an al-Qa'ida operative - whose leader has been able to circumvent the military and intelligence authorities of the greatest power on earth - really be so mouse-like when confronted with Saudi checkpoints?
A cynic might suggest a different scenario: that the Saudis and al-Qa'ida have somehow done a deal, that al-Qa'ida will be left in peace if a few members ritually turn themselves in, along with a promise not to bomb the kingdom again. Sending Bin Laden and his legions to Afghanistan was, in the first place, a way to get them out of Saudi Arabia. For years, Bin Laden was in contact with Prince Nayef's predecessor as Interior Minister.
All of which raises another question: if Osama bin Laden is not in Afghanistan or Pakistan, could he perhaps be in Saudi Arabia, where he has more support than anywhere else in the Arab world, even among the royal family?