I would like to thank the Dade County Medical Examiner’s Office for putting up with me for a week, and particularly Dr. Charles Wetli, whose patience talking with someone trained in Ophthalmology and Surgery instead of Forensic Pathology was extraordinary. I would also like to thank Dr. Charles Hirsch, Chief Medical Examiner for the City of New York, for his hospitality, and Dr. Jackie Lee for her willingness to share a glimpse into the more personal side of Forensic Pathology.

Last, but not least, I would like to thank Jean Reeds, whose intuitive sense of psychology makes her support, advice, and criticism inordinately valuable.

The cocaine shot into Duncan Andrews’ antecubital vein in a concentrated bolus after having been propelled by the plunger of a syringe. Chemical alarms sounded immediately. A number of the blood cells and plasma enzymes recognized the cocaine molecules as being part of a family of compounds called alkaloids, which are manufactured by plants and include such physiologically active substances as caffeine, morphine, strychnine, and nicotine.

In a desperate but vain attempt to protect the body from this sudden invasion, plasma enzymes called cholesterases attacked the cocaine, splitting some of the foreign molecules into physiologically inert fragments. But the cocaine dose was overwhelming. Within seconds the cocaine was streaking through the right side of the heart, spreading through the lungs, and then heading out into Duncan ’s body.

The pharmacologic effects of the drug began almost instantly. Some of the cocaine molecules tumbled into the coronary arteries and began constricting them and reducing blood flow to the heart. At the same time the cocaine began to diffuse out of the coronary vessels into the extracellular fluid, bathing the hardworking heart muscle fibers. There the foreign compound began to interrupt the movement of sodium ions through the heart cells’ membranes, a critical part of the heart muscle contractile function. The result was that cardiac conductivity and contractility began to fall.

Simultaneously the cocaine molecules fanned out throughout the brain, having coursed up into the skull through the carotid arteries. Like knives through butter, the cocaine penetrated the blood brain barrier. Once inside the brain, the cocaine bathed the defenseless brain cells, pooling in spaces called synapses across which the nerve cells communicated.

Within the synapses the cocaine began to exert its most perverse effects. It became an impersonator. By an ironic twist of chemical fate, an outer portion of the cocaine molecule was erroneously recognized by the nerve cells as a neurotransmitter, either epinephrine, norepinephrine, or dopamine. Like skeleton keys, the cocaine molecules insinuated themselves into the molecular pumps responsible for absorbing these neurotransmitters, locking them, and bringing the pumps to a sudden halt.

The result was predictable. Since the reabsorption of the neurotransmitters was blocked, the neurotransmitters’ stimulative effect was preserved. And the stimulation caused the release of more neurotransmitters in an upward spiral of self-fulfilling excitation. Nerve cells that would have normally reverted to quiescence and serenity began to fire frantically.

The brain progressively brimmed with activity, particularly the pleasure centers deeply embedded below the cerebral cortex. Here dopamine was the principal neurotransmitter. With a perverse predilection the cocaine blocked the dopamine pumps, and the dopamine concentration soared. Circuits of nerve cells divinely wired to ensure the survival of the species rang with excitement and filled afferent pathways running up to the cortex with ecstatic messages.

But the pleasure centers were not the only areas of Duncan ’s brain to be affected, just some of the first. Soon the darker side of the cocaine invasion began to exert its effect. Phylogenetically older, more caudal centers of the brain involving functions like muscle coordination and the regulation of breathing began to be affected. Even the thermoregulatory area began to be stimulated, as well as the part of the brain responsible for vomiting.

Thus all was not well. In the middle of the rush of pleasurable impulses, an ominous condition was in the making. A dark cloud was forming on the horizon, auguring a horrible neurological storm. The cocaine was about to reveal its true deceitful self: a minion of death disguised in an aura of beguiling pleasure.

Duncan Andrews’ mind was racing like a runaway train. Only a moment ago he’d been in a groggy, drugged stupor. Within seconds his dizziness and lethargy had evaporated like a drip of water falling onto a sizzling skillet. A rush of exhilaration and energy consumed him, making him feel suddenly powerful. It was as if he could do anything. In a glow of new clarity, he understood he was infinitely stronger and smarter than he’d ever realized. But just as he was beginning to savor this cascade of euphoric thoughts and this enlightened view of his abilities, he began to feel overwhelmed by intense waves of pleasure he could define only as pure ecstasy. He would have shouted for joy if only his mouth could form the proper words. But he couldn’t speak. Thoughts and feelings were reverberating in his mind too rapidly to vocalize. Any fear or misgivings he had been feeling only minutes ago melted in this newfound rapture and delight.

But like his torpor, the pleasure was short-lived. The blissful smile that had formed on Duncan ’s face twisted into a grimace of terror and panic. A voice called out that the people he feared were returning. His eyes darted around the room. He saw no one, yet the voice continued its message. Quickly he looked over his shoulder into the kitchen. It was empty. Turning his head, he looked down the hallway toward the bedroom. No one was there, but the voice remained. Now it was whispering a more dire prediction: he was going to die.

“Who are you?” Duncan screamed. He put his hands over his ears as if to block the sound out. “Where are you? How did you get in here?” His eyes again raced searchingly about the room.

The voice didn’t answer. Duncan didn’t know it was coming from inside his head.

Duncan struggled to his feet. He was surprised to realize he’d been on his living room floor. As he rose, his shoulder bumped against the coffee table. The syringe that had so recently been in his arm clattered to the floor. Duncan stared at it with hatred and regret, then reached for it to crush it between his fingers.

Duncan ’s hand stopped just short of the syringe. His eyes opened wide with confusion mixed with a new fear. All at once he could feel the unmistakable itch of hundreds of insects crawling on the skin of his arms. Forgetting the syringe, Duncan held out his hands with his palms up. He could feel the bugs squirming all over his forearms, but no matter how hard he searched he couldn’t see them. His skin appeared perfectly clear. Then the itch spread to his legs.

“Ahhhhhh!” Duncan screamed. He tried to wipe his arms, guessing the insects were too small to be seen, but the itching only got worse. With a shiver of profound fear it dawned on him that the organisms had to be under his skin. Somehow they had invaded his body. Perhaps they had been in the syringe.