 Complete the following phrase:  Dolgorukov was initially allowed to stay in the city when he arrived at the end of April, but was arrested by the Cheka secret police, along with Count Ilya Tatishchev, as enemies of the socialist revolution, after maps of the region showing river routes were allegedly found in his lodgings. During imprisonment, Dolgorukov constantly pressured the British Consulate in Ekaterinburg to help the Imperial family, using pencil-written notes smuggled from his prison cell. Accused of plotting to rescue the Imperial family, Dolgorukov and Tatishchev were taken by Bolshevik revolutionary Grigory Nikulin and Cheka agents beyond the citys Ivanovskoe Cemetery on July 10, shot in the head and thrown into a pit. Nikulin went on to 