CAIRO // Twice, the jailed Habib El Adly turned down requests for interviews from investigators probing the tumultuous events of 2011 that transformed Egypt forever.
But several weeks after the first petitions in early August last year, the warden of Cairo's Tora Prison, where El Adly is being held, sent a message saying Egypt's most-feared security official under Hosni Mubarak had reconsidered.
"Habib El Adly wishes to speak," the warden said.
It was a watershed moment for a fact-finding commission that was established by Mohammed Morsi last June to investigate the killing of protesters during the turbulent transition from the start of the uprising in January 2011, to Mr Morsi's swearing-in as president more than 17 months later.
The investigators would finally be able to put their questions to a key figure in the crackdown that left more than 800 dead in the 18 days of demonstrations that forced Mubarak out. They would be able to find out the truth of what happened during those history-altering days.
Or so they thought.
Instead, what came next during five hours of video-recorded questioning of El Adly at the prison went to the heart of why, two years after the uprising, the pursuit of justice and accountability in Egypt remains elusive and the truth of what exactly happened is still shrouded in mystery, speculation and rumours of conspiracy.
When a member of the committee presented El Adly with documentation that showed live ammunition was checked out to police officers during the protests, he denied any knowledge of that taking place.
"He said the police must have disobeyed his orders to only use tear gas and batons," said Mohsen Bahnasi, 51, a human rights lawyer and member of the steering committee of the commission who reviewed footage of the questioning.
"There is no proof for what he said, but there is also no proof that he ordered killing. We only have the log books showing ammunition was checked out."
The commission was made up of 16 people, including representatives of the ministries of interior and justice, the military, human-rights lawyers and families of the people killed during protests. They investigated 22 events from January 25 to Mr Morsi's inauguration. In each, they found proof that people were killed with bullets and also uncovered a series of mysteries that may never be solved.
El Adly's response to being presented with the log books could easily summarise the whole project, Mr Bahnasi said.
It was no surprise that they struggled with their inquiries. The institutions that investigate crimes and oversee security - the police, the state security, the intelligence agencies - are themselves accused of crimes, making them reluctant participants in digging into the past. Evidence has been lost or burnt in unexplained fires; witnesses have given contradictory statements; and the officials who oversaw the government's response to the huge demonstrations will not budge.
The allegations investigated by the commission are just one side of the game of mysteries used by different political forces to cast aspersions on their enemies. Former members of the Mubarak's National Democratic Party and those opposed to the Muslim Brotherhood have their own unanswered questions: how was it possible that dozens of police stations were attacked simultaneously during the uprising and who orchestrated the sieges on prisons that led to the release of dozens of Islamists.
Yousry Abdel Razek, a lawyer who has been an outspoken defender of Mubarak, said the Egyptian people had been duped into believing there had been a democratic revolution.
"There was a conspiracy from afar and from within," he said of the 18-day uprising, describing how he believes the Brotherhood struck a deal with Hamas and other Islamist groups to help break their members out of prison. "The revolutionaries make claims, but cannot prove it."
Yet, asked if he had access to Mubarak or detailed information about the family's finances, he would say only that his job was to ask the other side for proof. "It's not the job of a lawyer to prove the defence unless the accuser can prove their case," he said.
With the announcement last week that Mubarak and El Adly would be retried on criminal charges of responsibility in the deaths of protesters, the abiding mysteries of the past two years have again been thrust centre stage.
Khaled Fahmy, a historian at the American University of Cairo, said that the pursuit of truth is itself a "revolutionary act".
The questions also reveal the nature of the opposition to the new president and his supporters.
"This is part of the political moment of engaging the Brotherhood or embarrassing them or attacking them," he said. "It's not just a desire by some distant academics to figure out what happened during a historic moment. It is part of an ongoing political struggle. Like all major events, it's not about the past, it's about the present and future."
Mr Fahmy's own project, a documentation of those events for the Egyptian National Archives, has suffered from the opacity of the government and the reluctance of witnesses to give testimony for fear of reprisal from the police, army and state security.
What is more, he claims memory is more of a prism from which the world is viewed than a straightforward recollection of events.
He recently remembered an event from January 28, 2011 that he hadn't thought about since that day. A police officer on the Kasr El Nil bridge ended up isolated from his fellow officers and was attacked by protesters. Several protesters formed a cordon around him and escorted him back to the other side.
"I don't know why I forgot that," he said. "Memory plays tricks."
A 781-page report prepared by the commission, which has not been published, is now under review by a team at the public prosecution to determine if new charges could be levied against Mubarak and other officials. There is still uncertainty about whether Mubarak and El Adly could face a stronger sentence than the life imprisonment they received in the original trial, and about how new evidence can be used.
One of the most prominent leaks from the report was that Mubarak had a specialTV feed in his palace showing the events in Tahrir Square. Mr Bahnasi, a member of the commission's steering committee, said it was proof that Mubarak's claims of ignorance of what was happening on the streets were not true.
But Ahmed Ragheb, a member of the commission, believes the furore over the television feed was just hype. The far more damning evidence was the logs showing live ammunition was checked out of police and army arsenals. .
"Yes, it's a fact that Mubarak had a TV feed," he said. "But knowing this is not going to help us build a new Egypt. For that we need to know what happened in the streets with the police and the army. Who killed the Egyptian people? This is the big question we tried to answer."