VISBY, Sweden — “The colonel told me he wouldn’t accuse me of gun possession,” my cellmate Nabil Shurbaji told me happily one evening in June 2012. We were sitting in a dark, damp corner, in our torn clothes. Our bodies were covered with blisters and open wounds. Some were caused by daily beatings and electric shocks, some by scabies. Bed bugs swarmed over everything.

We cleaned our bodies and clothes twice a day, under a faint lamp. We took turns, in groups of four or five, but there were always more bugs. They were among our worst nightmares, in addition to the jailers above us.

The bug-infested cell where we were held was part of an air force intelligence center near the Mezzah military airport in Damascus. The center was under the supervision of Maher al-Assad, the brother of President Bashar al-Assad and one of the most feared men in Syria’s security services. After the revolution broke out in March 2011, the airport became the site of interrogations of members of the opposition.

Nabil was thrilled about not being falsely accused of gun possession, a charge that was being leveled against many of those held alongside us. Gun possession charges, we believed at the time, could lead to a life sentence, or worse, a death sentence. (I later discovered, while investigating Syria’s prisons, that being accused of using a gun can often be better than being a peaceful activist, doctor or journalist. One former jailer cited a twist on a cliché: “The pen is more dangerous than a gun.”)