"It is not all over yet," Wade said quietly.
Ellsworth stared, as did Grantham and Carton. "You mean—" the President began.
"I mean that I know at last who the Invisible Master is and where he is!" said Wade.
Ellsworth seemed too astounded to speak, but Grantham leaned to grasp Wade's arm. "Is that true, Wade?" he asked. "You've actually found him?"
"I have," Wade told them quietly.
And then as the three others stared at him he went on. "You remember, Grantham, that you told me that in a case like this the ordinary police-routine, the gathering of fact after fact to apprehend a criminal, was useless? You may have been right, but I followed that routine and I've finally gathered among other facts, three facts that tell me everything I want to know about the Invisible Master. Had I had these three facts last night I could have saved us that struggle and Kingston's life, but I did not have them then. I have them now, though."
"And the three facts?" Grantham asked. Ellsworth was staring as though bewilderedly, Carton leaning tensely forward.
"The first fact," said Wade, "is something that President Ellsworth happened to say the other night—when we spoke of Gray—saying how Grantham and he had been hampered in their scientific work by lack of funds, and how it would be almost justifiable to take some of the city's pleasure-spent millions for the aiding of research."
They were all silent. Ellsworth's face had flushed.
"The second fact is one that not all of you may understand and that I myself was ignorant of until last night—it is the peculiar optical properties of tourmaline crystals."