Maddox reached in his pocket to pull out his automatic. The gun caught as he hurried.

The old lawyer picked up his revolver. He was on his knees, steadying himself with one hand as he fired hastily with the other. Had his aim been sure, he would have ended the fray. But the old man’s strength had gone; his hand wavered and the shot went wide.

Then came an answering report as Maddox loosed a bullet into the lawyer’s body. Zachary Mitchell collapsed upon the floor.

Excitedly, Maddox picked up Mitchell’s revolver. He gathered the sheet of paper with its mapped symbols, the letter and the key. He stood uncertainly in the center of the room; then spied a small rug near the door.

He stooped forward and turned down one corner of the rug. Then, he hurriedly left the apartment.

Scarcely had the door closed before the man on the floor began to move. Bob Maddox, fearful of further shots, with their attendant noise, had taken it for granted that Zachary Mitchell was dead.

In that he was not far wrong. The old man was dying. But he groped forward along the floor to the chair where Maddox had been sitting.

There his hand encountered the pencil with which the young man had been tracing the plan of the map. With an effort, Mitchell raised himself to the table. On a sheet of paper, he wrote the name of the killer — the name he had learned in the telephone warning.

Maddox shot me.

Mitchell’s hand faltered. The pencil dropped from nerveless fingers.