The White operation began in May 1925, when a female Intelligence Service agent, claiming to be a Swiss bohemian called Pia Merz, arrived in Moscow on a Swiss passport issued on November 21, 1921, number 37059, to begin working for an orphanage. She, like Ruslana Havrysh, worked for the Intelligence Service part-time, only when asked.
The White surveillance teams who had been monitoring Yurovsky for weeks knew he often drove down a narrow road called Sayan Street on his way to and from his apartment and his workplace in the city. Intelligence Service headquarters in Sremski Karlovci, Yugoslavia, decided that the combatant, who had been trained well for her position, would take up residence in a flat in Moscow that overlooked Vozdvizhenka Street and collect information about Yakov Yurovsky. So on July 2, 1925, Pia Merz rented an apartment on the seventh floor of what had been a luxury building. From her apartment in the Ilarion Yerokhin building she could see Sayan street. Merz rented the place for three months, paying 150 rubles up front. Posing as a middle-aged eccentric spinster, Merz made sure that her neighbors took note of her harmless idiosyncrasies. She spent most of her time feeding unwanted neighborhood cats, sitting in her window wildly painting the streets below, and helping to control a vast surveillance operation against Yurovsky.
Other White agents then began arriving in the city. According to Cheka investigators, an Intelligence Service agent using the name Oskar Dusl, and traveling on a fake Austrian passport (no. 215388) arrived in Moscow a week after Merz had rented the apartment. He rented a small room at the Melody Hotel, bought a used car, and started badgering local shopkeepers, offering to sell them a variety of Austrian kitchen utensils. The Intelligence Service certainly went to enormous lengths to ensure their agents had excellent covers; Dusl eagerly distributed leaflets for his range of exciting products around Moscow.
Elias Schiegg, the cover name for a third White arrived a day later on a forged Swiss passport (no. 371977, dated April 5, 1919) and rented a room at the Tiflis Hotel.
By early July 1925, the Whites were ready to launch their attack against the dark gentleman. At dusk one evening two army engineer divers left an ROVS-owned ship anchored off the Gulf of Finland and slipped ashore at a deserted beach carrying a heavy package containing explosives and detonators. Waiting for them nearby were two White agents; on receiving a predetermined code from the diver’s flashlight, they left the motor of their Peugeot and went to collect the pack.
As the two divers slipped back into the water and rowed their small boat quietly back to their ship, the other two agents returned to their safe house. They took twelve funts (11 lbs) of TNT back to Moscow with them.
Several days later, several agents, disguised as workmen, closed off a section of Sayan Street, putting up a construction sign saying utility repairs were in progress. The “repairs” consisted of planting the TNT beneath a manhole, on a metal base that directed most of the blast upwards. A red mark that served as a guide was painted on the wall of a building across the street precisely in line with the center of the manhole. The command-wire, a hair-thin, bare copper strand that only the sharpest eye could see, snaked out of the small hole in the top of the manhole, underneath the Peugeot, which was carefully double-parked to force Yurovsky to drive directly over the charge.
The following day the street was opened again, but men were seen stringing wire at the end of the street. In response to inquiries they explained they were from the state electric power company. What they were actually doing was to string the command-wire from underneath the Peugeot, into the gutter and up a telephone pole on the sidewalk, where, forming an electric cable, it was stretched the length of Sayan Street alongside the telephone wires. Then, the cable dropped to street level. At the appropriate time, the split cable would be attached to an electric box hidden in a briefcase. The agents settled down to wait for Yurovsky to appear.
At 1636 hours on July 14, 1925, Yakov Mikhailovich Yurovsky bade farewell to his wife and jumped into his battered, tan Benz sedan that waited for him with its motor running. He was accompanied, as ever, by two heavily armed bodyguards who rode with him in the Benz and at least three more guards climbed into a Lorraine-Dietrich that followed them. Yurovsky was on the way to his sister’s house for a birthday party for his niece, his sister’s daughter, who turned fifteen that day. A camera had been purchased for the occasion. An Intelligence Service agent was watching from nearby as the small convoy left, and he alerted the remaining members of the team that Yurovsky was on the move. From her corner apartment, Pia Merz watched and waited for Yurovsky to appear. Dusl and Schiegg, in electricians’ uniforms, waited around the corner. Dusl was up on a ladder, briefcase in hand.