IMPOSTURE: Hunters become the hunted in this gripping murder mystery by Ray Clark (book series for 10 year olds TXT) 📕

“Nitrogen mustards were originally produced in the 1920s and 1930s, potentially as chemical warfare weapons,” said Fitz. “They are vesicants, or to be more precise, blister agents, similar to the sulfur mustards. They come in different forms that can smell fishy, musty, soapy, or fruity. They can be in the form of an oily-textured liquid, a vapour, or a solid. But I don’t believe it was a solid. I still think he was injected with the liquid form of the agent.”

The mention of the word agent made Gardener shudder involuntarily. That led to nerve agents, which could lead to government involvement, especially when you considered where most nerve agents came from.

“But there is another complication that you might need to investigate,” said Fitz.

“Go on,” said Reilly, having risen from his seat to pour another coffee.

“They are also known by their military designations of HN-1, HN-2, and HN-3. To my knowledge,” continued Fitz, “nitrogen mustards were never used in warfare. HN-1 was originally designed to remove warts. It was later identified as a potential chemical warfare agent. HN-2 was designed as a military agent, but that was used in cancer treatment. Other treatment agents now have replaced it. HN-3 however, was designed solely as a military agent.”

“Has anyone used it?”

“Certainly not us.”

“Is it contagious?” asked Gardener.

“If nitrogen mustards are released into the air as a vapour, you could be exposed through skin contact, eye contact, or breathing. If it’s released into water, then you’d be exposed if you drank the contaminated water, or getting it on your skin.”

“But you think this was injected in liquid form, so how likely is the exposure?”

“Very slight,” replied Fitz. “You could be exposed by coming into direct contact with liquid nitrogen mustards but I don’t believe either of you were.”

“Is there an antidote if you are?” asked Reilly.

“No,” said Fitz. “No antidote exists for nitrogen mustard exposure, the best thing to do is avoid it.”

“Now he tells us.”

“So which one of the three do you think he was given?” asked Gardener, not relishing the answer, or its implications.

“Without the results of the toxic screen I won’t know for definite, but in my opinion he was given HN-3.”

“And you’d get that where?” asked Reilly.

Fitz sat back, deep in thought. “There are any number of places on the black market, if you know the right people or the right place to look. If you two are going to start anywhere there’s only one place I know in the UK.”

“Go on,” said Gardener.

“Porton Down.”

Chapter Thirty-eight

Downstairs in a bathroom unit at the rear of the building, the driver opened a cupboard. Reaching inside he selected a sealed vial of iodine, and a vitamin supplement for Zoe Harrison.

His hand shook when he slipped it into the box of syringes. Before he even extracted the bloody thing he could feel his forehead sweating and his legs weakening.

He placed them in a small Boots bag before leaning back against the wall, calming his breathing.

When he felt ready he stood up straight, smiling about the fact that his prisoner thought she’d be given Carbimazole, a pro drug used to control an over-active thyroid; it stopped the thyroid gland from making too much thyroid hormone. Clearing out her riverside apartment, he had studied Zoe’s medicine cupboard. A couple of hours’ worth of research, both on the internet, and studying all her paperwork in a small wall safe she kept hidden behind an oil painting – how original – and he knew exactly what she was suffering from.

That had led him into researching things that were bad for her. People with hyperthyroidism should avoid preparations high in iodine because it can make the condition paradoxically worse. Additionally, in certain people it could provoke hypothyroidism.

Once he had emptied her cupboards he very carefully drained the sealed bottles of Carbimazole, replacing it with iodine, which was now beginning to take its toll. But it wouldn’t be for much longer.

She really needed to avoid products such as kelp. They would almost certainly interfere with the thyroid function. He knew kelp was derived from seaweed, naturally high in iodine. According to Google, it was sometimes marketed as a “thyroid booster”. He’d purchased it in dry preparations and tablets, grinding up both. As with iodine, kelp would have no health benefits for her at all.

Something else to avoid was soya, which also interfered with thyroxine absorption. That was more of a problem for him. She did not drink tea or coffee, or hot drinks of any description, only energy drinks. Soya milk would have been perfect.

Feeling calmer, he left the bathroom and headed up the stairs two at a time. He opened the door. She was still sitting at her desk, her hands flying across the keyboard. Suddenly, as he closed the door, she went into a spasm, wrapping her hands around her stomach.

“About time,” she said, through gritted teeth. “God only knows what’s wrong with me.”

He put the small bag on the table, retreating to the door, and standing with his back to it. Not that she would try to escape but he was taking nothing for granted.

She pulled everything out of the bag, inspecting it. She held the sealed packet containing the syringe in the air, at arms’ length to her, and a little closer to him than he would have liked. His breathing quickened. He was beginning to wonder if she had cottoned on and was taunting him. All his research had told him that Zoe Harrison was by far the sharpest tool in the box. He was going to have to watch her more carefully.

Another forceful movement, probably another spasm, resulted in Zoe dropping the syringe.

The driver felt it was deliberate, as she’d made sure she