Hanaud lit a cigarette and took his time.

“What I think is this.  The man who drove the car into Geneva drove it back, because—­he meant to leave it again in the garage of the Villa Rose.”

“Good heavens!” cried Ricardo, flinging himself back.  The theory so calmly enunciated took his breath away.

“Would he have dared?” asked Harry Wethermill.

Hanaud leaned across and tapped his fingers on the table to emphasise his answer.

“All through this crime there are two things visible—­brains and daring; clever brains and extraordinary daring.  Would he have dared?  He dared to be at the corner close to the Villa Rose at daylight.  Why else should he have returned except to put back the car?  Consider!  The petrol is taken from tins which Servettaz might never have touched for a fortnight, and by that time he might, as he said, have forgotten whether he had not used them himself.  I had this possibility in my mind when I put the questions to Servettaz about the petrol which the Commissaire thought so stupid.  The utmost care is taken that there shall be no mould left on the floor of the carriage.  The scrap of chiffon was torn off, no doubt, when the women finally left the car, and therefore not noticed, or that, too, would have been removed.  That the exterior of the car was dirty betrayed nothing, for Servettaz had left it uncleaned.”

Hanaud leaned back and, step by step, related the journey of the car.

“The man leaves the gate open; he drives into Geneva the two women, who are careful that their shoes shall leave no marks upon the floor.  At Geneva they get out.  The man returns.  If he can only leave the car in the garage he covers all traces of the course he and his friends have taken.  No one would suspect that the car had ever left the garage.  At the corner of the road, just as he is turning down to the villa, he sees a sergent-de-ville at the gate.  He knows that the murder is discovered.  He puts on full speed and goes straight out of the town.  What is he to do?  He is driving a car for which the police in an hour or two, if not now already, will be surely watching.  He is driving it in broad daylight.  He must get rid of it, and at once, before people are about to see it, and to see him in it.  Imagine his feelings!  It is almost enough to make one pity him.  Here he is in a car which convicts him as a murderer, and he has nowhere to leave it.  He drives through Aix.  Then on the outskirts of the town he finds an empty villa.  He drives in at the gate, forces the door of the coach-house, and leaves his car there.  Now, observe!  It is no longer any use for him to pretend that he and his friends did not disappear in that car.  The murder is already discovered, and with the murder the disappearance of the car.  So he no longer troubles his head about it.  He does not remove the traces of mould from the place where his feet rested, which otherwise, no doubt, he