A year ago, Iranian soldiers arrested three Americans along the border with Iraq.
Accused of espionage and of crossing illegally into Iran, which says it has "evidence" of contact with US intelligence agencies, they have been in prison ever since.
But the three friends say they were innocent hikers, inadvertently caught up in a regional tug of war between archenemies Iran and America.
The US news magazine The Nation in June cited Iraqi eyewitness accounts stating that Sarah Shourd, Shane Bauer, and Josh Fattal were arrested on the Iraqi side of the poorly marked border by Iranian guards who briefly crossed a few yards into Iraq to pick them up. It reported that the man likely responsible for their arrest – the head of the Revolutionary Guard intelligence for the region – has since been imprisoned for a string of kidnappings and murders.
Iran raised hopes of imminent release in May by allowing the prisoners' mothers to visit their children in Tehran, laying on good food, flowers, and a hotel reunion for the cameras. Iranian officials cited "humanitarian" reasons – a gesture not typically accorded spies.
"After a few days of interrogation I assume the Iranian government quickly figured out that their accusations of espionage were baseless," says Karim Sadjadpour, an Iran specialist at the Carnegie Endowment for International Peace in Washington, who has been advising the families.
So why are they still being held?
The Islamic Republic has a history of using hostages to make political statements, from the 1979 takeover of the US Embassy in Tehran – when 52 Americans were held for 444 days – to more recent arrests of dual nationals accused of fomenting a Velvet Revolution against the regime.
In the 1980s, the United States engaged in secret arms-for-hostages deals with Tehran – part of the larger Iran-contra scandal – to secure the release of Americans kidnapped in Lebanon. Top Iranian officials have suggested a trade in this case, too, which Washington has dismissed.
"It's evident that the Iranian government sees the three hikers as bargaining chips, but what's frustrating about this case is that it's not precisely clear what the regime wants in return for them," says Mr. Sadjadpour. "Moreover, the US government has always been averse to making deals with hostage takers, fearful that it rewards bad behavior and [gives incentives] to continue such practices."
"Who is going to decide?" says Mr. Nourizadeh, a frequent critic of the regime. "Is it the Revolutionary Guard? [President Mahmoud] Ahmadinejad? The Iranian Intelligence Ministry?... Nothing is really clear in Iran now."
The case bubbled to the surface again last month during the bizarre saga of young Iranian nuclear scientist Shahram Amiri, who apparently redefected to Iran after a year in the US, claiming the CIA kidnapped him. Now back in Tehran, Mr. Amiri asserts that US agents pressed him to agree to be swapped for the three US "spies."
Tehran may be biding its time. "The Iranians believe they may at a later stage get much more than what is on the table now in return for releasing these three," says Nourizadeh.