It was a red car, crowding the state limit for speed, and it swept down on Thompson with a subdued purr like a great cat before a fire.  When it was almost abreast of him there burst from it a crack like the report of a shotgun.  There was just a perceptible wabble of the machine.  Its hot pace slackened abruptly.  It rolled past and came to a stop beside the road fifty yards along—­a massive brute of a red roadster driven by a slim girl in a pongee suit, a girl whose bare head was bound about with heavy braids of corn-yellow hair.

Thompson half rose—­then sank back in momentary indecision.  Perhaps it were wiser to let sleeping dogs lie.  Then he smiled at the incongruity of that proverb applied to Sophie Carr.

He sat watching the machine for a minute.  The halting of its burst of speed was no mystery to Thompson.  Miss Carr proceeded with calm deliberation.  She first resurrected a Panama hat from somewhere in the seat beside her and pinned it atop of her head.  Then she got out, walked around to the front wheel, poked it tentatively once or twice, and proceeded about the business of getting out a jack and a toolkit.

By the time Thompson decided that in common decency he should offer to lend a hand and thus was moved to rise and approach the disabled car she had the jack under the front axle and was applying a brace wrench to the rim bolts.  But the rim bolts that hold on a five-inch tire are not designed to unscrew too easily.  Sophie had started one with an earnest tug and was twisting stoutly at the second when he reached her.  He knew by the impersonal glance she gave him that he was to her merely a casual stranger.

“May I help you?” he said politely.  “A big tire is rather hard to handle.”

Sophie bestowed another level look upon him as she straightened up from her task.  A puzzled expression showed briefly in her gray eyes.  But she handed him the wrench without parley.

“Thanks, if you will,” she said.  “These rim bolts are fearfully stiff.  I daresay I could manage it though.  I’ve done it on a lighter car.  But it’s a man’s job, really.”

Thompson laid off his coat and set to work silently, withholding speech for a double reason.  He could not trust his tongue, and he was not given to inconsequential chatter.  If she did not recognize him—­well, there was no good reason why she should remember, if she chose not to remember.  He could lend a hand and go his way, just as he would have been moved to lend a hand to any one in like difficulty.

He twisted out the bolt-heads, turned the lugs, pulled the rim clear of the wheel.  He stood up to get the spare tire from its place behind.  And he caught Sophie staring at him, astonishment, surprise, inquiry all blended in one frank stare.  But still she did not speak.

He trundled the blow-out casing to the rear, took off the one ready inflated, and speedily had it fast in its appointed position on the wheel.