Here was a matter that might at last lead to a solution of the difficulty. Again on fire with hope, she interviewed her father. He was certain that a donation had been promised, he had thought the envelope handed him by Mr. Marcy contained the gift--but of the donation itself he knew no more. She interviewed Doctor Sherman; he had heard Mr. Marcy refer to a donation but knew nothing about the matter. She tried to get in communication with Mr. Marcy, only to learn that he was in England studying some new filtering plants recently installed in that country. Undiscouraged, she one day stepped off the train in St. Louis, the home of the Acme Filter, and appeared in the office of the company. The general manager, a gentleman who ran to portliness in his figure, his jewellery and his courtesy, seemed perfectly acquainted with the case. In exculpation of himself and his company, he said that they were constantly being held up by every variety of official from a county commissioner to a mayor, and they were simply forced to give "presents" in order to do business. "But my father's defense," put in Katherine, "was that he thought this 'present' was in reality a donation to the hospital. Was anything said to my father about a donation?" "I believe there was." "That corroborates my father!" Katherine exclaimed eagerly. "Would you make that statement at the trial--or at least give me an affidavit to that effect?" "I'll be glad to give you an affidavit. But I should explain that the 'present' and the donation were two distinctly separate affairs." "Then what became of the donation?" Katherine cried triumphantly. "It was sent," said the manager. "Sent?" "I sent it myself," was the reply. Katherine left St. Louis more puzzled than before. What had become of the check, if it had really been sent? Home again, she ransacked her father's desk with his aid, and in a bottom drawer they found a heap of long-neglected mail. Doctor West at first scratched his head in perplexity. "I remember now," he said. "I never was much of a hand to keep up with my letters, and for the few days before that celebration I was so excited that I just threw everything----" But Katherine had torn open an envelope and was holding in her hands a fifty dollar check from the Acme Filter Company. "What was the date of your arrest?" she asked sharply. "The date Mr. Marcy gave you that money?" "The fifteenth of May." "This check is dated the twelfth of May. The envelope shows it was received in Westville on the thirteenth." "Well, what of that?" "Only this," said Katherine slowly, and with a chill at her heart, "that the prosecution can charge, and we cannot disprove the charge, that the real donation was already in your possession at the time you accepted what you say you believed was the donation."