"I expected to write you a letter about this. But," with a grin, "aviation's too full of ifs, so--thought I might as well attend to it now while we're together. You saved my life. And you're not the kind of a chap I can get a reward off on. But there's something I want to do for you, and this note will tell you what." He slid the piece of paper into Hal's pocket, then climbed up into his plane.