The U-shaped hallway on the sixth floor of the old Sanlam Building is altogether unremarkable. Just a series of brown-wood and white-metal doors with a shower room at one end - the trappings of a low-rent tenement hall that the place has become.
But if you know what to look for, you'll find marks left over from another era, when this was one of the most infamous corridors of apartheid. For here is where Steve Biko, the charismatic leader of the Black Consciousness Movement who died in detention in 1977, walked for the last time.
Mojalefa Vinqi knows what to look for. A few months after Biko was here, Mr. Vinqi was brought through on his way to Robben Island, where he spent five years as a political prisoner.
Just to the left of the elevators, in which black police beat detainees before handing them over to their white superiors, concrete patches indicate where a coded security gate was once bolted down. Empty light sockets sit above the heavy, five-inch metal doors leading into thick, sound-proof vaults. When a red light glowed in the sockets, a prisoner was being tortured.
"They were very careful to make sure nobody knew what was happening here," Vinqi says.
The images here are fragments of a story that has never been told by those who know it with certainty. But as South Africa remembers the 20th anniversary of Biko's death today, they remain important.
The Truth and Reconciliation Commission (TRC), a panel charged with investigating apartheid-era crimes, sits in a nearby township, questioning the five Special Branch police officers who conducted his final interrogation. As the hearings proceed, those hoping to learn the truth of Biko's demise are disappointed. The five admit they concocted a version of events in 1977; now, their individual testimonies are conflicting variations of the old line.
"I don't believe that we are very much near the truth," says George Bizos, lawyer for the Biko family. "The applicants" - the five officers seeking amnesty in exchange for their testimonies - "are not being forthcoming. But there are important contradictions."
On the morning of Sept. 6, 1977, Steven Bantu Biko, who had been in detention the previous 18 days, was brought to the Sanlam Building.
Five men - Harold Snyman, Daniel Siebert, Jacobus Beneke, Rubin Marx, and Gideon Nieuwoudt - interrogated him. Six days later he died.
The Special Branch officers claimed that Biko had become enraged during questioning, that a scuffle broke out, and that Biko hit his head on a wall while being subdued.
At the time of the inquest in 1977, almost nobody had access to the sixth floor. Now, however, as the same men alter their stories, it is possible to measure their words against where they did their work.
Few who have stood inside the white-doored vaults, for instance, might be surprised at Colonel Snyman's admission this week that the Special Branch applied torture as a means of interrogation.
Little on the sixth floor is as relevant or revealing as the size of room 619. A simple rectangle, it is at the same time small enough and large enough to verify what are perhaps the two most important changes of story to come from the TRC hearings.
Snyman said Wednesday he was in the room throughout the interrogation. He claims he never saw what three of his colleagues now contend: that Nieuwoudt struck Biko with a piece of hose pipe.
"How could you not see this?" Mr. Bizos asked him during cross-examination. "Were you hiding behind a metal cabinet?"
At least two of the five - Snyman and Mr. Beneke - also stood by their earlier explanation that Biko must have injured himself when he fell during the scuffle and hit his head against a wall. But in his application to the TRC, Mr. Siebert alleges that he, Nieuwoudt, and Snyman started in one corner and ran Biko head-first into a far wall like - as Bizos put it - "a battering ram." If never proved, the dimensions of the room nonetheless show that this version is at least plausible.
Examining Biko's demise, however important to South Africa's search for truth, is only part of the many ways in which this country is remembering the legacy of its fallen freedom fighter this week. In East London, notables from around the world have come for the unveiling of a new statue.
Today, the Black Consciousness Movement, which Biko led, is rededicating itself as a political entity.
Perhaps, though, Biko would be most moved by people like Thandisekile Mnyimba, a business student at nearby Vista University, who still seems inspired by what the fallen man taught.
"The white regime tried to teach the black people that they are inferior," he says. "Biko said, 'Love yourselves first, before you entreat the enemy.' That is what we've tried to do."