ON 12 February 1894 an unassuming petit bourgeois named Émile Henry threw a dynamite bomb into the ‘upper-class’ Café Terminus near the Parisian Saint-Lazare railway station, killing one and severely injuring twenty. Although the reasons behind the act were varied and convoluted, having as much to do with Henry's doctrinaire idealism as with his pathological personality and difficult family history, chief amongst them had been a desire to avenge Auguste Vaillant, the guillotined comrade behind the ill-fated attempt to blow up the Chamber of Deputies.

The anarchist den at 30 Fitzroy Street had been of interest to Scotland Yard ever since Meunier had briefly lodged there in the summer of 1892. A couple of days after the outrage at Café Terminus, such interest must have only increased considerably, especially as Henry had been seen at that address ‘only a few weeks [before]’ crossing the Channel back to France. Among the building's more recent frequenters was also a twenty-seven-year-old journeyman tailor by the name of Martial Bourdin. In anarchist circles he was not a figure of any consequence – although he was related by marriage to Henry Samuels, the notorious editor of Commonweal – but all the same, Bourdin envisioned himself as a man on a mission.

On 15 February, around 3.30 p.m., Bourdin left Soho and headed towards Westminster Bridge where he boarded the 379 tram running to East Greenwich station. In the left pocket of his heavy overcoat was a small paper-wrapped parcel about the size of a brick. As the tram pulled into East Greenwich station, Bourdin got off in a hurry, stopping only to ask the station time-keeper the way to Greenwich Park. By 4.45 p.m., Bourdin reached the base of the zigzag pathway leading up to the Royal Observatory just as two park labourers were coming down. Noticing Bourdin was carrying a small parcel and walking very fast, they passed him by, continuing their conversation. It was the last time anyone saw him in one piece.

Around 4.50 p.m. a loud boom, slightly less powerful than a cannon's report, was heard all throughout the park and as far away as Stockwell Street. Rushing towards the place of the explosion, a park-keeper found Bourdin kneeling in a pool of blood at the first bend in the uphill pathway.