Tate’s Lane, when they reached it, was deserted save for a single policeman patrolling slowly towards its far end.
“When he goes round the corner we’ll have our opportunity,” said French, who had looked up the areas covered by all the adjacent beats.
They waited in York Street until the man disappeared, then followed him down Tate’s Lane. Two minutes later they were at the coachbuilder’s.
“Now for it,” said French, glancing quickly round.
No one was in sight. Opposite, the houses were in darkness except for a single lighted window, which showed a dull yellow square against the surrounding gloom. Rather a nuisance, French thought. Someone over there was awake and might chance to look out.
“I’ll go first,” he whispered.
Ormsby laid his glass against the wall, and forming a back, gave French a hoist up on to the wall. A moment later French had dropped softly to the ground within. Quickly the glass and tools were handed over, and in ten seconds more Ormsby also was inside.
They stood listening, but the silence was reassuring, and they tiptoed to the garage and set to work on the window. French directed the beam from his torch and held up the coat to screen the light, while Ormsby tackled the removal of the glass.
The night was ideal for their purpose. There was no moon, but the light of the stars showed up faintly the larger objects, while allowing the men to work unseen. It was calm and sounds carried far. In the street they could hear the footsteps of the returning policeman ring sharply.
Soon the putty was cut away and the sprigs withdrawn. Then, affixing rubber suckers to the corners, Ormsby pulled. This was the critical operation, but he worked skilfully and gradually one corner after another came away and he was able to lift out the pane.
“Fine,” French whispered. “Now a hand in.”
A flash from the torch showed that there was a small bench beneath the window. With difficulty French squeezed through on to the bench and dropped noiselessly to the floor. Immediately he opened the door, Ormsby slipped in, and the door was shut.
Their first care was to rig the coat over the window lest the light should betray them. Then while Ormsby started on his doorkey, French with the other torch examined the car.
His search was extraordinarily thorough. From tires to roof and from headlights to numberplate he went over every detail. But absolutely without result. The car was a perfectly normal 15/20 Mercury saloon, probably worth £450 when new. It was upholstered in grey leatherette and the small fittings were complete and excellent in quality.
With a helpless, baffled feeling, French stood pondering. Were all his ideas of the affair erroneous? Did these girls really use the car only to register bets with the driver?
For a moment he thought it must be so. Then the face of poor pretty Thurza Darke came up before his imagination as he had seen it in the Portsmouth police station. No. There was something in their drives more deadly and sinister than gambling. Crime, terrible and dastardly, lurked there.
Setting his jaw grimly, he turned back to the car. There must be something.
He sat down once more on the back seat, and stooping forward as the girls had done, marked the area which his fingers could reach. On that space he worked, examining joints, testing for secret springs, measuring cubic capacities. And then suddenly he found what he wanted.
Beneath the back seat was the petrol tank. This he had already measured and dipped, and it had seemed to fill the entire space. But now he found that a thin steel plate, hinged along the floor, turned up in front of the tank. It fitted so well that at first he had taken it for the front of the tank itself. But he had accidentally pressed a secret spring, and the plate had moved forward. Attached to the inside of the plate, and fitting into a recess in the tank, was a small steel pocket, lined with velvet. The recess was triangular in cross-section, which explained the fact that he had been able to push Ormsby’s steel rule right down to the bottom of the tank, and even feel round its edges, without discovering the trick.
French breathed a sigh of relief. At last the action of the girls was clear. On entering the car they had stooped down, lowered the plate, put in or taken out some object, raised the plate again and dismounted. After arrival from his round, or before starting, Welland had emptied or filled the pocket.
But beyond the admittedly crucial point that his suspicions had been proved justified, French had learned nothing. That the objects transmitted were small was now certain, but this had been probable from the first.
In vain he searched for some fragment in the velvet lining of the pocket which might indicate the nature of the transitory contents. In vain he longed for the skill of Dr. Thorndyke, who might have been able with his vacuum extractor to secure microscopic dust from its fibres, which would have solved the problem.
Satisfied that he had learnt all he could from the car, he turned to the examination of the building itself.
There was not much to examine. The four walls, unbroken save for door and window, were finished smoothly with cement. Under the window was the bench, a plain structure offering no hiding place. The roof was not ceiled, the rafters, slating laths, and slates being visible. The floor was of concrete, sloping slightly towards the central pit. A four-inch drain level with the bottom of the pit
