In 1989, an unknown number of demonstrators, many of them students, were killed after protesting the Chinese government in Tiananmen Square. The massacre became infamous, but those who died were not the only victims of the government crackdown. Hundreds of protestors were also detained—and tomorrow, reports Simon Denyer for The Washington Post, the final imprisoned protestor will be released after 27 years in prison.

His name is Miao Deshun, and he was imprisoned after being accused of arson for throwing a basket at a burning tank. As Denyer reports, Deshun suffers from hepatitis B and will leave prison mentally ill. He is known to have been tortured after refusing to admit guilt and will likely be surveilled by state police even after his release.

Deshun was just 25 when he joined in the pro-democracy protests at Tiananmen Square, writes Tom Phillips for The Guardian. He was initially given a death sentence, but his sentence was since reduced, and observers write that he has not received visits from family members for over a decade, though that was reportedly by his own request.

People like Deshun originally gathered in Tiananmen Square to mourn the head of a pro-democratic student movement, but their mass mourning turned to protest when they began to make demands of their government. As Tim Leslie writes for ABC Australia, their unrest was fueled by capitalist reforms that stoked corruption and stymied wages for students and professors.

On the nights of June 3 and 4, 1989, government tanks drove into the square to break up the demonstrations. Several hundred to more than 2,000 people died, though numbers are still hotly disputed, and prisoners were detained in 11-foot-by-11-foot cells that held 16 prisoners apiece and fed two meager meals a day.

A lot has changed in China since Deshun was arrested. As Zheng Wang writes for TIME, the Tiananmen Square crackdown prompted the Chinese government to become more conservative politically and more liberal economically. Though China’s politics still look much as they did in 1989, the physical and economic landscape of the country Deshun is soon to reenter has morphed dramatically, and even the most isolated areas of the country have become more modern.

But though the world will watch as Deshun is released, his fellow Chinese people are less likely to be aware of his years of imprisonment. The massacre is not mentioned in Chinese textbooks and mention of it in the media is strongly censored. For now, the memory of Tiananmen Square in China is a kind of open secret—one that the world must remember even as the Chinese government tries to forget.