He strolled on, turned a corner and, crossing a road, he came to where one great garden served for a double row of middle-class houses. The backs of these houses opened on to the square. He looked round and, seeing the coast clear, he clambered over the iron railings and dropped into the big pleasure ground, holding very carefully an object that bulged in his pocket.

  He took a leisurely view of the houses before he decided on the victim. The blinds of this particular house were up and the French windows of the dining-room were open, and he could see the laughing group of young people about the table. There was a birthday party or something of the sort in progress, for there was a great parade of Parthian caps and paper sunbonnets.

  The man was evidently satisfied with the possibilities for tragedy, and he took a pace nearer…

  Two strong arms were about him, arms with muscles like cords of steel.

  'Not that way, my friend,' whispered a voice in his ear…

  The man showed his teeth in a dreadful grin.

  The sergeant on duty at Notting Hill Gate Station received a note at the hands of a grimy urchin, who for days afterwards maintained a position of enviable notoriety.

  'A gentleman told me to bring this,' he said.

  The sergeant looked at the small boy sternly and asked him if he ever washed his face. Then he read the letter:

  'The second man of the three concerned in the attempt to blow up the Tower Bridge will be found in the garden of Maidham Crescent, under the laurel bushes, opposite No. 72.'

  It was signed 'The Council of Justice'.

  The commissioner was sitting over his coffee at the Ritz, when they brought him the news. Falmouth was a deferential guest, and the chief passed him the note without comment.

  'This is going to settle the Red Hundred,' said Falmouth. 'These people are fighting them with their own weapons—assassination with assassination, terror with terror. Where do we come in?'

  'We come in at the end,' said the commissioner, choosing his words with great niceness, 'to clean up the mess, and take any scraps of credit that are going'—he paused and shook his head. 'I hope—I should be sorry—' he began.

  'So should I,' said the detective sincerely, for he knew that his chief was concerned for the ultimate safety of the men whose arrest it was his duty to effect. The commissioner's brows were wrinkled thoughtfully.

  'Two,' he said musingly; 'now, how on earth do the Four Just Men know the number in this—and how did they track them down—and who is the third?—heavens! one could go on asking questions the whole of the night!'

  On one point the Commissioner might have been informed earlier in the evening—he was not told until three o'clock the next morning. The third man was Von Dunop. Ignorant of the fate of his fellow-Terrorists, he sallied forth to complete the day notably.

  The crowd at a theatre door started a train of thought, but he rejected that outlet to ambition. It was too public, and the chance of escape was nil. These British audiences did not lose their heads so quickly; they refused to be confounded by noise and smoke, and a writhing figure here and there. Von Dunop was no exponent of the Glory of Death school. He greatly desired glory, but the smaller the risk, the greater the glory. This was his code.

  He stood for a moment outside the Hotel Ritz. A party of diners were leaving, and motor-cars were being steered up to carry these accursed plutocrats to the theatre. One soldierly-looking gentleman, with a grey moustache, and attended by a quiet, observant, cleanshaven man, interested the anarchist. He and the soldier exchanged glances.

  'Who the dickens was that?' asked the commissioner as he stepped into the taxi. 'I seem to know his face.'

  'I have seen him before,' said Falmouth. 'I won't go with you, sir— I've a little business to do in this part of the world.'

  Thereafter Von Dunop was not permitted to enjoy his walk in solitude, for, unknown to him, a man 'picked him up' and followed him throughout the evening. And as the hour grew later, that one man became two, at eleven o'clock he became three, and at quarter to twelve, when Von Dunop had finally fixed upon the scene and scope of his exploit, he turned from Park Lane into Brook Street to discover, to his annoyance, quite a number of people within call. Yet he suspected nothing. He did not suspect the night wanderer mooching along the curb with downcast eyes, seeking the gutter for the stray cigar end; nor the two loudly talking men in suits of violet check who wrangled as they walked concerning the relative merits of the favourites for the Derby; nor the commissionaire trudging home with his bag in his hand and a pipe in his mouth, nor the clean-shaven man in evening dress.

  The Home Secretary had a house in Berkeley Square. Von Dunop knew the number very well. He slackened pace to allow the man in evening dress to pass. The slow-moving taxi that was fifty yards away he must risk.