Alexei Navalny, Russia's most outspoken critic of President Vladimir Putin, is fighting for his life in a hospital, and his spokeswoman says she believes Navalny was poisoned as he was flying from Siberia back to Moscow. Navalny is unconscious and on a ventilator, spokeswoman Kira Yarmysh, who had been traveling with the opposition leader, said via Twitter. Navalny drank some tea at the airport in Tomsk, Yarmysh said, and he began feeling unwell shortly after his commercial flight took off. His deteriorating condition prompted the plane's pilots to make an emergency landing at Omsk, some 550 miles away. A doctor...