"Sometimes."
"If you have half an hour to spare this evening, look at that—and do me the favor of telling me what it means."
She offered something to him, which appeared in the dim light to be only a sheet of paper. He hesitated to take it from her. She tried to press it on him.
"I found it among my husband's papers," she said. "He was a great chemist, as you know. It might be interesting to you."
He still hesitated.
"Are you acquainted with chemical science?" he asked.
"I am perfectly ignorant of chemical science."
"Then what interest can you have in interpreting the cipher?"
"I have a very serious interest. There may be something dangerous in it, if it fell into unscrupulous hands. I want to know if I ought to destroy it."
He suddenly took the paper from her. It felt stiff, like a sheet of cartridge-paper.