Rosabelle was quite sure she understood what he was driving at. She would have dared anything for her lover, and if it was a question of smuggling Mr. Gideon Lane into her uncle’s room while he was in the city, her woman’s wit, sharpened by her love, would find a way. “Now we will not waste time,” said the genial Mr. Lane as the excited girl rose to take her leave. “Pending the obtaining of your uncle’s permission to do the thing openly, I want you to co-operate with me in a little matter. Pay Mr. Croxton a visit as soon as possible and get him to give you an impression of his fingers. If you tell him what you want it for, he cannot refuse.” “But, of course, he will not refuse,” cried the girl a little indignantly. “Would he have let me come to you if he was not prepared to face the ordeal? And if you find, as you will, that the finger-marks on the safe are not his, that will establish his innocence once and for all, will it not?” Mr. Lane seemed a trifle embarrassed by the question. “It will go a long way,” he said, speaking with some hesitation. “Why not the whole way?” demanded Rosabelle, and her eyes flashed a little. “Miss Sheldon, it is better you should not ask me too many questions till we are more sure of our ground. We experts require a great deal of evidence before we venture to say of any accused man that he is absolutely innocent or absolutely guilty.” “But if the finger-marks are proved not to be his, how can he be guilty?” she cried obstinately. “You force me to say what I would rather leave unsaid. But our investigations would not be very useful if we refused to weigh not only every probability, but also every possibility. You say that your uncle firmly believes in this young man’s guilt, although he loved him and treated him like a son. If he still maintains that belief, is it not open to him to say that if Richard Croxton was not the actual thief, he was an accomplice or an accessory? How otherwise could the actual thief have got the necessary knowledge of that safe’s complicated mechanism? Please understand I am not advancing this as my own opinion, but as one that might be entertained.” And for the first time poor Rosabelle began to see how very hard was the task before them. The tears came into her eyes. “Oh, Mr. Lane, what will be wanted to prove his absolute innocence? I see too clearly the terrible difficulties in our way.” The great detective spoke very gravely. “The surest way of proving Mr. Croxton’s innocence is by discovering beyond any possibility of doubt the person who opened that safe, and proving that that person, whoever it may be, had no connection with him. To that point my investigations will tend, with what results it is impossible for me to foresee.”