‘This man,’ he thought, ’is in a blue fright; and moreover, and although he smokes a deal of rank tobacco, I am open to bet he is a butcher by trade.’

He relaxed the pressure of his fingers very slightly, and the hand was sharply withdrawn.

Almost at the same moment the doctor’s own hand went swiftly to his head.  There was a tug at the reins, and it fetched old Dapple up with a sprawl.

‘My hat is gone!’ exclaimed the doctor.

Sure enough it was:  and as he leaned and peered after it, he could just discern it for a moment before it dropped like a sable bird against a dark furze bush a few yards away to the left.

‘My hat is gone,’ he repeated.

His companion did not budge, hardly so much as turned a glance, but sat as before, shivering and dumb.

‘I am very sorry to trouble you, ma’am,’ ventured the doctor politely.  ’But would it inconvenience you very much to climb down and recover my hat?  It lies yonder, against the furze.  With one of the lamps you will find it easily.’

‘Can’t you climb down yourself and fetch it?  I’ll hold the reins.’  The voice was husky, the tone ungracious.

’No, ma’am.  Dapple is restive to-night, and I prefer—­if you’ll forgive me—­not to trust him to a lady and a stranger.  If you refuse, my hat must e’en remain where it lies.’

The figure rose, as if upon a sudden resolve, and set one foot on the step.

’I’ll fetch it for you.  But being driven to-night is cold work, and I won’t trouble you any further.  Hand me down my bag, please.’

The stranger climbed out and stood beside the step, with one hand holding on to the edge of the footboard.

‘Come, hand me down my bag.’

For answer Doctor Unonius lifted his foot and brought it down suddenly on the hand, grinding his heel into the fingers.  At the same moment the whiplash fell over Dapple’s haunches.  There was a yell of pain, a wild curse, a scuttering of hoofs, and the old horse, unaccustomed to the whip and well-nigh scared out of his senses, plunged forward into the night.

For a minute or so Doctor Unonius, as he called to Dapple and plied the whip, fancied that in the intervals of these encouragements he caught the sound of footsteps pursuing him down the hard road.  But the chase, if chase were given, was vain from the first:  for Dapple tore along as though the devil himself sat behind the splashboard.

But while the gig swayed and rocked, and while the wind sung past his ears, Doctor Unonius thrust a foot out, and steadying it against the hard bag, enjoyed some crowded moments of glorious life.  After all these sedentary years adventure had swooped on him out of the night and was wafting him along in a sort of ecstasy.  If the hand were, after all, a woman’s, he could never forgive himself. . . .  But it was not:  of that he felt sure.  Complete success had crowned his simple manoeuvre.  He felt all the exhilaration of a born student who suddenly discovers he can be practical—­the sort of exhilaration Cicero felt, to his surprise, in dealing with the conspiracy of Catiline, and never during the rest of his life forgot.