The man stopped the car, slid over in the seat, said dubiously, “I don’t like this. You ain’t even got a monkey wrench.”

Mason swung his long legs over the back of the front seat, jackknifed his slim figure, slipped in behind the steering wheel, and snapped the car into second gear, easing back the clutch as he pressed the foot throttle. The car slid smoothly forward. Mason swung it into a sharp turn, snapped the gear shift into high, and fell in behind the ambulance.

The blood-red rays of the spotlight from the car ahead made a sinister pencil of light. A siren screamed. Mason, moving the wheel of the rented car with deft skill, kept the machine within a few feet of the rear of the ambulance, following through the traffic in the pathway cleared by the spotlight and siren.

The man who had been driving the car gripped the back of the front seat with his left hand, held to the edge of the door with his right. “Good Lord,” he moaned. “I didn’t know it would be like this! ” His face was strained with nervous tension. Several times he instinctively pressed down with his feet against the floorboards as though trying to put on the brakes. Once when collision seemed imminent, he reached for the ignition switch. Mason, batting his hand away, stepped on the throttle and avoided the oncoming car.

“Don’t be a fool,” Mason said without taking his eyes from the road. “No chance to stop on that one. Using the throttle was our only chance. If you hesitate, you’re licked.”

Della Street, in the back of the car, hanging on to the robe rail, her heels braced against the foot rest, watched the kaleidoscope of traffic which flashed past the windows of the speeding automobile. Her lips were half parted; her eyes sparkling. The driver of the car, looking back to her for moral support to back up his demand for less speed, abruptly changed his mind and concentrated simply on hanging on.

The ambulance cut its way through traffic, to slow down in front of the red brick structure of a rambling hospital.

Mason left the ambulance as it turned into the emergency entrance. He swung his car around to the front of the hospital, parked it, and said to the driver, “Here’s the monkey wrench I was holding over your head.”

He handed him three ten-dollar bills.

The driver put the money in his pocket wordlessly.