Roger gave his evidence concisely to a hushed court. Raeburn’s friends took in every word, obviously impressed, and once or twice even Raeburn looked anxious. But nothing disturbed Melville.

He rose to his feet as Roger finished. “I wonder if I may put one or two questions to the witness, Your Worship?”

“You may, Mr Melville.”

“Thank you, sir.” Melville stood in front of the witness box, still rubbing his hands together. “Knowing your excellent reputation, Chief Inspector, I take it for granted that on behalf of the police you exerted yourself in every way to endeavour to find an eyewitness of this occurrence?”

“I did,” said Roger.

“Did you succeed?”

“No.”

“Did you succeed in finding anyone who was on Clapham Common at the time the incident occurred?”

“Yes,” said Roger.

“May I ask if you intend to produce that person as a witness?”

“Yes.”

“And may I ask who he—or she—is?” went on Melville, with a glance at the magistrate.

“Is that necessary, since we are told that the person will be called to give evidence?” interrupted the magistrate.

“I think perhaps we shall progress more rapidly if the witness would answer the question,” said Melville.

“Very well—you may proceed.”

Roger said: “A police constable was cycling across the Common about the time of the incident.”

“A police constable. I see. Wasn’t it a remarkable coincidence that a constable should happen to be on the Common at the crucial time—unless, of course, he was patrolling in the course of his duty? Is that the explanation?”

“He was returning from duty,” said Roger, coldly.

“Did he actually see the car?”

The magistrate leaned forward. “The witness will be able to answer for himself, Mr Melville.”

“Of course, Your Worship, of course. I am considering only the precious time of the court,” said Melville smoothly. “Setting aside the question of the fortuitous advent of the policeman who—er—happened to be crossing the Common at this time, but did not see what occurred, did you find any other person who was near the scene at the time?”