A series of horrifying crimes occurred on a cold autumn evening on Westminster Bridge, which crosses the Thames near the parliament building: three men were stabbed one after another. The public is in shock—because all three were members of Parliament, deputies of the House of Commons. Police inspector Thomas Pitt is tortured by the question: which direction should he look for the killer? A robber? But none of the victims was robbed. A political rally? Yet in life, the parliamentarians held different views on the most burning political issues. A provocation by anarchists? But the method of killing doesn’t fit—they prefer bombs…