In July 2005, when four al Qaeda prisoners slipped past guards at a high-security detention center at Bagram Air Base in Afghanistan, and then traversed half the country without getting caught, many found it hard to believe.
There are signs that even Osama bin Laden may have found the news of their breakout from a base that's home to 12,000 U.S. strained credulity.
Since then, two of the escapees seem to have become de facto spokesmen for al Qaeda: Libyan Abu Yahya al-Libi most recently appeared in a video tribute to Abu Musab al-Zarqawi, the slain leader of the Iraqi insurgency.
Saudi national Abu Nasser al-Qahtani, in the meantime, has been recorded delivering a speech to followers along the Pakistan-Afghanistan border, and then leading a nighttime attack on a coalition army base.
All told, the escapees have starred in or made cameo appearances in more than five al Qaeda videos.
So it's strange that bin Laden and his No. 2, Ayman al-Zawahiri, have never made a statement praising their stunning breakout or even rubbing Washington's nose in the fact that it happened.
It's a glaring absence in a year in which the two top al Qaeda leaders have issued an unprecedented 15 statements, paying tribute, for example, to al-Zarqawi (who was often considered a potential rival to bin Laden) and Hezbollah leader Sheik Hassan Nasrallah (despite his adherence to the Shiite sect of Islam, which al Qaeda despises).
Farouq al-Iraqi was recently killed fighting in Iraq. The other three are now believed to operate along the Pakistan-Afghanistan border, in somewhat lower-status roles than they previously held.
Al-Libi, for example, was previously thought to be a senior al Qaeda ideologist but was recently spotted in a video fighting under Abu Laith al-Libi, a commander of the Arab mujahedeen in southern Afghanistan.
Al-Qahtani is believed to train soldiers in eastern Afghanistan. In one video appearance, he bemoans being told to "lay low" by his superiors and expresses hope that he will soon be handed a plum assignment to kill infidels.
Given that their cover was already blown, it's hardly surprising that the al Qaeda leadership might turn the escapees into their video frontmen and caution them not to wander too far afield.
"I have no doubt they have been fully reintegrated into al Qaeda," said ABC News consultant Rahimullah Yusufzai, who has reported on the terror network since its formation.
But sources in South Waziristan, Pakistan, said it is surprising that the men have been kept from planning meetings between senior al Qaeda leaders, which, they said, might indicate that the top leadership doesn't believe they can be entirely trusted.
And there may be good reason for that belief.
It's known that al Farouq al-Iraqi cooperated with American interrogators while in custody.
And then there's a report in a Saudi newspaper quoting the father of al-Qahtani as saying his son expressed regret over his ties to al Qaeda in letters he sent from Bagram.
"My father, please forgive me, because I was fooled and influenced by the satellite [channels] like many young men," he reportedly wrote in one letter. Another letter reportedly said, "Please forgive me, Mother. If I get out of this ordeal, I won't do anything else, but take care of you (and my father)."
Instead, al-Qahtani has made a series of chilling video appearances, which belie any hopes he might return home to take care of Mom and Dad.
"It still strikes me as incredibly stupid and risky for al Qaeda leaders to immediately let these guys back into the fold," said terror video analyst Evan Kohlmann. "It could be that Abu Nasser is acting, but if so, his performance is Oscar-worthy."