Soon after a private plane carrying poisoned Russian opposition leader Alexei Navalny touched down in Berlin last month, doctors treating him at the prestigious Charite hospital there became so alarmed they called in the army.
Navalny was certainly not suffering from low blood sugar, as the Russian doctors who first treated his mysterious illness had claimed, or even a standard detective-novel poison like arsenic or cyanide.
It was, the German doctors suspected, something far more dangerous, requiring the attention of the army’s chemical weapons specialists, German officials said.