Alexei Navalny, a critic of Putin, passes away in prison

. Compare that to the 19-year prison sentence he received last year on extremism charges, widely viewed to have been politically motivated. There were physical attacks, too. In 2017 his eyesight was damaged when he was splashed with a green antiseptic dye. Three years later in Siberia he was poisoned with a nerve agent and airlifted to Germany for life-saving treatment. He survived and accused the Kremlin of trying to murder him. And yet the following year - despite concerns for his safety - he returned to Russia. Why did he go back?