The warm air was thick and heavy, perfumed with a sweet scent that drifted lazily on the breeze.

Cameron thought it to be radiating from any one of the blossoms burgeoning in the crowded flowerbeds, but strangely enough it seemed to be more pungent inside the house than out. Even with her hand clasped tightly over her face the odour seeped through her fingers, snaking tendrils of vapour into her lungs.

"What is that smell?" Cameron called, her voice muffled by her hand.

"Benzene." Foreman called back, his voice similarly muted as he answered through his fingers.

"House was right. This place is loaded with the stuff."

"So what are we supposed to do now?"

"The guys from environmental health should be here any time now, we'd better wait outside."

Cameron strode as quickly as she could out of the house, her chest burning as she tried not to breathe and the heavy sound of Foreman's footsteps behind her.

Coming out into the open Cameron breathed deeply, the clean air refreshing to her senses. She and Foreman had been in the house for less than five minutes yet she had already begun to feel the intoxicating effects of the poisonous fumes.

"How bad do you think it is?" Cameron asked anxiously.

Foreman let out a long breath, and looked briefly back at the house.

"Judging by how strong that smell is and the fact that I feel dizzy after being in there for no more than a couple of minutes? I'd say it's bad."

"How could Jameson have lived in there for so long? His presentation was chronic, but Chase's… how does that make sense?"

Foreman shrugged, "The level of contamination must have increased. A broken pipe, a leaky valve – something's gone wrong in a serious way."

Frowning Cameron surveyed the street, taking in all the houses; the dusty cars waiting to be washed, the overgrown lawns waiting to be mown.

"How far do you think the effects of the gas have spread Foreman? Look at this street; everything looks… like it's dying."

Foreman too appraised the length of the road.

"You're right." He looked at Cameron. "It's not safe here. We should leave."

As they began to walk back to the car a small truck rounded the corner, pulling to a halt in front of Jameson's house.

"Are you from public health?" Foreman called as a tall, bearded man rose from the vehicle.

"Yeah, Rick Wallace," he said, "Who are you?"

"We're from PPTH – we're treating the owner of this residence" he indicated Jameson's house, "for what we think is benzene toxicity."

"Well," Rick said, "I can tell you now that you're right. That smell? Typical benzene – it's an aromatic hydrocarbon, usually used in industry." He paused, contemplating the surroundings, "It's almost certainly coming from the gas station."

"Are we safe?" Cameron asked, "From here, I mean."

Wallace wrinkled his nose, "For a while. We need to shut down the gas station though, clear out the local residents until the gas has dissipated."

"How many people is it likely to have affected?"

"Hard to tell. The intensity of the odour suggests a significant leak. You've only got the one patient?"

"Two. The owner or this place, and a colleague of ours."

"Acute presentation?"

"Our colleague, yes. But the owner of the house presented with chronic aplastic anaemia."

"Anaemia?" He let out a long whistle. "If he's been exposed long enough for the benzene to destroy the bone marrow then the leak isn't a new problem. There's most likely been some seepage for several months, maybe even years."

"So what do you do now?"

"Well, we'll obviously take some readings first. Air, soil, groundwater… but as I said, the gas station will almost certainly have to be closed and the residents moved temporarily. If what you say about the owner of this place is correct it might be an idea to get the locals in for a medical. Who knows what sort of damage has been done if the leak has been going on for years…"

"You know a lot about benzene?" Cameron asked, apprehensively.

Wallace grinned, "Sure do. Whilst it's not common benzene toxicity does crop up now and again."

"What's the prognosis? Generally speaking I mean, for acute poisoning?"

Wallace's face fell, the grin slipping away. He sighed before responding.

"Depends on the degree of exposure. Strictly speaking we're being exposed right now, but - " he cut in at the expression on Cameron's face, " – given the open environment the concentration of benzene is unlikely to do any significant harm. Inhalation in the region of fifty-parts per billion is enough to bring on the symptoms of acute toxicity, so is ingestion of anything greater than sixty-parts per million."

"But what about the prognosis?" Cameron pressed again.

Wallace again hesitated in responding, contemplating Cameron and Foreman with what looked like pity.

"Are we talking about your colleague?"

"Yes."

"Rapid onset? Breathing difficulty?"

Foreman nodded.

Wallace ran a hand through his beard, and sighed again.

"Like I said, it depends… prognosis is… It's tricky. There is no direct antidote, as it were, for benzene. Treatment is supportive." He shook his head apologetically, "You just have to do what you can and hope the body can repair itself."

A brief silence fell, broken after a moment by Rick Wallace smacking his hands together.

"Let's take some readings, eh? So we know what we're dealing with."

………………………

Several hours passed when Chase awoke to pain. His stomach contracted in spasms that gripped in a vice-like hold and refused to ease.

He tried to scream at the pain shearing through his body, but could not. His mouth was obstructed and he panicked, tearing at his face.

The sudden blaring of an erratic siren-like noise screeched through the air, alarming him further.

In a brief moment of clarity Chase recognised this as a heart monitor.

He could feel bile rising in his throat, and he tried to swallow it back, terrified of choking. His chest began to burn and he gasped in a futile attempt to force air into lungs that had seized in panic.

In that moment Chase knew he was dying. Black obscurity began to overcome him, clouding his vision and dulling his senses. The pain eased as the void overtook him, and he sank into it gratefully, letting it wash over him.

As the last thread of consciousness slipped away, the erratic noise ceased. In its place a high-pitched drone shattered the air. His eyelids fluttered closed, and as he succumbed to the darkness Chase knew his heart was no longer beating.