Last Updated 18 November 2013
Aymen Saadi's brief call to jihad began with dreams of fighting for an Islamic state in Syria and ended with a botched suicide bombing attempt in a crowd of foreign tourists in Tunisia.
Guards tackled the Tunisian teenager before he detonated his bomb at a presidential mausoleum last month south of Tunis.
Minutes earlier, a fellow bomber had blown himself up into a bloody mess across the sand at a popular beach resort a few kilometres away.
Saadi's mission may have failed, and the beach bomber killed only himself, but Tunisia's first suicide attack in a decade was shock enough for the small North African nation; the war with militant Islam was at its door.
Tunisia's interior's ministry says its initial investigation indicates Al Qaeda-linked group Ansar al-Sharia carried out the attempted twin bombing.
Saadi might not have reached Syria's battlefields, but his journey from middle-class student to would-be suicide bomber reveals how far that conflict has become a clarion call for homegrown jihadists.
The bloodshed in Syria - as in Afghanistan in the 1980s and 1990s and Iraq in the past decade - is drawing young foreign recruits into Islamist militant ranks only to spit them back out again to return home hardened by fundamentalist fervour and war.
Saadi now sits in a Tunisian jail, but his case and those of other Tunisian jihadists are a warning about how militants, many trained in Libyan camps and dispatched to battles in Aleppo and Idlib, may come back to haunt North Africa.
"My son talked about Syria, but never about anything here in his country," Saadi's mother Hayet told Reuters. "My son was manipulated by criminal bosses, terrorists; he was just an adolescent who talked about jihad."
Tunisia is hardly alone in worrying about jihadi backlash; the roll call of those drawn to the cause of Sunni Islamist rebels battling Syrian President Bashar al-Assad is long and
diverse - from veterans of Iraq and Chechnya to sons of London and Stockholm immigrants.
But after the Arab Spring revolts of 2011, North Africa is especially vulnerable. Hardline militants found fertile ground to spread their fundamentalist message in the political chaos of countries like Tunisia and neighbouring Libya.
The Maghreb is even more exposed after this year's French intervention in Mali. Fleeing from French troops, Al Qaeda and Islamist fighters slipped into lawless southern Libya, forming a base from which to threaten Western interests.
After the revolt that toppled President Zine el Abidine Ben Ali in early 2011, Tunisia is still in flux. Moderate Islamists oppressed by Ben Ali rose to power. But ultra-conservative Salafists - keen to impose an Islamic State - returned too, from
exile or prison.
Salafists have since taken over mosques, attacked art shows and alcohol sellers they see an un-Islamic.
A year ago hardline Islamists briefly stormed the U.S. embassy in Tunis and hoisted
a black jihadi flag in victory.
Under pressure after militants killed two opposition leaders this year, Tunisia's ruling moderate Islamists blamed local hardline group Ansar al-Sharia for the violence and branded it a terrorist group in a crackdown.
Now, where once they openly preached for an Islamist state under strict Sharia law, many Tunisian hardliners have gone underground, frustrated at repression by fellow Islamists
enjoying the benefits of government power.
Ansar al-Sharia leader Abu Iyad, a veteran of Afghanistan, has vanished, too. Before he fled, he called Syria, not Tunisia, the route for jihad. His loyalty to Al Qaeda's regional vision has not been lost on his followers.
"We want nothing less than an Islamic state in Tunisia, and across the region. The first step must be Syria," Abu Salah, a young Salafist told Reuters in Tunis. "I am proud of our brothers in Syria, and I will go there myself in a few weeks."
FOOTBALL VERSUS FUNDAMENTALISM
Tunisia's Mediterranean beaches, popular with European tourists, and its proud secular tradition - among the strongest in the Arab world - make the former French colony of 11 million people seem an unlikely source for jihadists.
Nothing about Saadi's hometown Zarghouan, just 51 kilometres east of Tunis, suggests a cradle of extremism. It is best known for small sweet round donuts known as Kaak Warka pastries.
Saadi's family, too, is one of middle-class Tunisian moderation; an engineer father, a teacher mother, a white-daubed family home and a garden filled with orange and lemon trees.
In the teenager's room, a postcard of Bob Marley sits on a bookshelf next to Harper's Shorter English dictionary.
By his mother's account, Saadi was open-minded, and his high school grade book is dotted with "excellent" marks, in German, English and History. He was also a keen footballer, playing striker for the municipal football team.
But, she says, his views began to change about a year ago.
She recalls no one incident that triggered the shift, but he started to spend long hours scanning radical Islamist websites and drifted to ultra-conservative preachers at a mosque.
Then he argued that he should not attend a mixed-sex school.
"He was just like other boys. He played football, listened to music, joked with girls," Hayet said on the terrace of the family home.
"At the end of 2012 he changed; he grew a beard, threw away his jeans and wore the jilbeb," she said, referring to the long traditional gown favoured by Salafists.
His parents alerted authorities once to stop him going to Syria in March this year. But, she says, in August, he told them he was going to the beach with friends. He called several times - once from a Turkish number and on another occasion from a
Libyan one - but he never came back. He refused to say where he was.
The next time she saw him he was behind bars.
According to his mother, who spoke to her son in prison and his lawyer a week ago, Saadi told investigators he spent time near Benghazi, training with militants there in preparation to go to Turkey and then Syria.
But his commanders eventually sent him back to Tunisia.
"He wanted to go to Syria. My son told investigators the leaders called on him to carry out the attack in Tunisia," Hayet said. "He hesitated, but he thought they would kill him."
ROAD TO ALEPPO
Abu Talha, 23, a Tunisian Salafists from a town close to the Libyan border, made it to Syria. He told Reuters he spent six months fighting alongside an Islamist brigade in Aleppo last year before returning to Tunis because of family obligations.
Photographs show him with his Islamist brigade in Syria and earlier, dressed like a tourist for a flight to Turkey to evade authorities before crossing into northern Syria.
Wary of giving too much detail, Abu Talha, who like most Salafists used a nickname in interviews with Reuters, said he was not linked to any Tunisian group. He said he flew directly to Istanbul and had contact with fighters in the south of Turkey before crossing with them to a camp on the outskirts of Aleppo.
A Syrian commander trained them with AK-47 rifles, rocket launchers and pistols for a month. They read the Koran and took religious classes when not training.
"We trained with young men from Morocco, Jordan, Chechnya, Algeria. It was a group of about 100 together," he said.