"I was watching him. He had no time, or chance, to play a trick. The blank paper was there, and nothing else. It was writing paper, quite a lot of sheets that seemed to have been taken from some train, 'Santa Fé Limited,' or a name like that."
Beverley gave a cry, as if she had been struck over the heart.
"Let me think," she groaned. "How can that have been? Writing paper taken from the train?"
Suddenly she turned, and came back to the bed, putting out her hands in a groping way to Clo. The girl caught and held them tightly. They were very cold.
"Angel! is there nothing I can do?" she whispered.
Beverley sank on the bed once more.
"My head feels as if I'd been given ether," she said. "I can't think things out clearly. That isn't like me! A terrible day! One shock after another. If I talk to you, will you swear by all that's sacred never to give away one word?"
"I swear by my love for you. That's the most sacred thing I have, except my locket with mother's picture," the girl answered.
"You see," Beverley went on, "I've no one else but you, Clo. If I told my husband anything, I should have to tell all. I daren't do that. Not because I couldn't trust him. But I've taken an oath ten times more solemn than the one you took just now, to keep a secret that isn't only mine. Another's life depends on the secret being kept. To save that life I was forced to do what I hate to think of. And it's no concern of yours, but it would be Roger's if he had the faintest inkling! Now, I'm going to tell you one or two things, and you must use your brains to explain the mystery. You're clever, and true as steel. You've proved that! Suppose a case; suppose you'd undertaken a dangerous mission. You have in your charge some documents which could make or break a man. You know you'll be followed. You nearly miss your train, but you jump on board at the last minute. You see a man—not the one you expect, but another just as much to be feared—more, perhaps, because he's a great deal cleverer, if not so violent. You think you're lost, but you find a friend, a man who helps you. You give him the envelope that has the papers in it—a sealed envelope. You've seen it, Clo! He keeps it through the journey. At a stopping place on the way he offers to hand it back to you, but you refuse. You feel that the thing is safer with him. Later, in New York, he returns the envelope intact, the seals unbroken. This friend who comes to the rescue is the soul of honour. Never since that moment has the envelope been out of your own keeping. Yet it is opened to-day for the first time, and the papers that were in it are gone, changed for stationery of that train, the 'Santa Fé Limited.' How can this have been done? Who did it?"
"The other man must have done it, the one who followed you on to the train."