But while they plotted and schemed, Harrison Grant and Billy Cavanaugh were making their way up the rickety stairway that led to the bacteriologist's laboratory in the attic of a ramshackle building on Avenue A. A quick twisting of the knob and it yielded. Harrison Grant and his operative fumbled a moment in the darkness, then finding the switch of a table light, began their search. Desk by desk, drawer by drawer. Papers, musty old books on the development of cultures, newspaper clippings on the progress of the war, letters from Germany and at last---- An ejaculation from Harrison Grant. "Just what I thought!" he announced as he opened a small memorandum book. "The attempt against us tonight was an afterthought. A sort of a vacation of death, as it were. This man was brought to this country from Germany for one purpose--the propagation of germ cultures to be used against American workmen in munition factories, steel-mills, mines and other industries furnishing supplies to the Allies!" "Impossible!" Billy Cavanaugh's eyes went wide with horror. Harrison Grant pointed. "There's the evidence," he answered as he pointed to the notes of a memorandum book he had brought from the desk. "Let's see what the rest of it has to offer." A long silence, except for the crinkling of the pages as Harrison Grant read the notations in the old book. A long silence then---- "Careful there!" "What's the matter?" Harrison Grant paused with a finger in the air. Billy Cavanaugh reached forward, and taking the finger in his hand, lowered it. "Nothing--only you were about to touch that to your lips--and there's no telling how many different kinds of germs are on the pages of that book." Harrison Grant smiled. "Thanks, Billy," he said softly, then turned to his work again. A moment more and he had risen, his eyes wide, excited. "Get a telephone, quick!" "What's Up?" "A good deal. Wasn't there something in the paper tonight about trouble with the 'longshoremen?" "Yes--but it's all settled up. That is, the indications are that it will be settled. Why?" "Because it's far from settled. Look here!" A finger pointed to a scrawled line in the old memorandum book. Slowly the words were translated: "Special notation--germs for 'longshoremen if agitation fails." "And agitation has failed!" Harrison Grant said quickly. "Agitation has failed--and that means some other attempt against the 'longshoremen. It means----" "But the bacteriologist is dead. He won't carry out his orders."