Among the horrific images coming out from Sednaya, the pandemonium of Assad’s prison hell, is a swollen face bearing the marks of torture. It is the face of Mazen al-Hamada. Two moles on his right cheek, a protruding jaw, gaunt features: enough for those who've met him to recognize him, even when inanimate. As Sednaya’s gates opened, many were asking after Mazen, who had disappeared four years ago when he risked a return to Syria. His sister, Amal al-Hamada, came to identify his body at the morgue of Damascus' al-Mejtahed Hospital. The 47-year-old activist had been executed just days before ‘the slaughterhouse’ where he was being detained was liberated and the regime he’d spent years speaking out against was toppled.“I spoke to a doctor, sent him some photos, and he told me that he'd certainly been executed by hanging ten days ago," Amal...