Prothero started in pursuit.  He glimpsed the dog-cart turning into Bridge Street.  He had an impression that Benham used the whip at the corner, and that the dog-cart went forward out of sight with a startled jerk.  Prothero quickened his pace.

But when he got to the fork between the Huntingdon Road and the Cottenham Road, both roads were clear.

He spent some time in hesitation.  Then he went along the Huntingdon Road until he came upon a road-mender, and learnt that Benham had passed that way.  “Going pretty fast ’e was,” said the road-mender, “and whipping ’is ’orse.  Else you might ’a thought ‘e was a boltin’ with ’im.”  Prothero decided that if Benham came back at all he would return by way of Cottenham, and it was on the Cottenham Road that at last he encountered his friend again.

Benham was coming along at that good pace which all experienced horses when they are fairly turned back towards Cambridge display.  And there was something odd about Benham, as though he had a large circular halo with a thick rim.  This, it seemed, had replaced his hat.  He was certainly hatless.  The warm light of the sinking sun shone upon the horse and upon Benham’s erect figure and upon his face, and gleams of fire kept flashing from his head to this rim, like the gleam of drawn swords seen from afar.  As he drew nearer this halo detached itself from him and became a wheel sticking up behind him.  A large, clumsy-looking bicycle was attached to the dog-cart behind.  The expression of Benham’s golden face was still a stony expression; he regarded his friend with hard eyes.

“You all right, Benham?” cried Prothero, advancing into the road.

His eye examined the horse.  It looked all right, if anything it was a trifle subdued; there was a little foam about its mouth, but not very much.

“Whoa!” said Benham, and the horse stopped.  “Are you coming up, Prothero?”

Prothero clambered up beside him.  “I was anxious,” he said.

“There was no need to be.”

“You’ve broken your whip.”

“Yes.  It broke. . . .  Get up!”

They proceeded on their way to Cambridge.

“Something has happened to the wheel,” said Prothero, trying to be at his ease.

“Merely a splinter or so.  And a spoke perhaps.”

“And what is this behind?”

Benham made a half-turn of the head.  “It’s a motor-bicycle.”

Prothero took in details.

“Some of it is missing.”

“No, the front wheel is under the seat.”

“Oh!”

“Did you find it?” Prothero asked, after an interval.

“You mean?”

“He ran into a motor-car—­as I was passing.  I was perhaps a little to blame.  He asked me to bring his machine to Cambridge.  He went on in the car. . . .  It is all perfectly simple.”

Prothero glanced at the splinters in the wheel with a renewed interest.