Rachel Sargeant - The Good Teacher - A gripping thriller from the Kindle top ten bestselling author of ‘The Perfect Neighbours’

He’s a strategist, a mathematician, a man of reason – and speculation. It’s a case of horses for courses. The creases in his face deepen into a grin. He marvels at his gift for irony. Police duties take him away from his real work, although he has to admit that the income is useful. The allowance and expenses – thank the Lord for travel claims and a DCI who doesn’t probe them.

Only Mary probes. In the early years of their marriage, he tried to explain the nature of his empirical investigations. But she isn’t a scientist. He has no time to listen to her weakminded debates and to counter her abstract reasoning. He’s taken the pragmatic line and concealed his research, continuing in secret to build the necessary experience to achieve results.

He scans the page again. He must have missed it. He drains his cup. His head begins to ache but he forces the print back into focus. Suddenly, there’s The Evidence. Yes, The Evidence, but are the conditions viable? He snatches up a page of formulae and scribbles in the numerical values. The first equation balances. Now to manipulate the figures on the second one. Adrenaline starts its familiar stampede around his body. One more test needed, then it will be irrefutable. He roots through a pile of charts and diagrams and retrieves some graph paper. Hand shaking, he plots the data and joins the crosses. There it is, a straight line. Better than he’d dared hope. Perfect positive correlation. It’s incontrovertible. After so many challenges – not sacrifices, as Mary called them – here is the eureka moment.

With his eyes fixed on the newsprint, his right hand opens his top drawer and his left dials the sacred number.

It takes an age to be answered. Such impudence. He has an urgent theory to verify.

At last. “The name is Tarnovski. I have an account.” He takes the whisky bottle out of the drawer and refills the cup.

“What limit?… I can’t hold. There isn’t time.”

During the silence on the phone line, he strains to make sense of the buzzing sounds from his radio.

“I see. And you can’t override it? I’m a long-standing account holder … Well, of all the nerve. Wait a minute …” Another confounded woman who doesn’t understand the science. He slides open the top drawer again and removes a debit card from underneath a second, empty, bottle. It slips in his clammy fingers.

“It’s the eleven thirty at Lingfield. I want to place …” He hesitates as another, weaker, force tugs against his resolve: Sara’s gap-year fund. But he’ll be more than able to replenish it. And retrieve his wristwatch from the pawnbrokers. A statistician of his standing doesn’t miscalculate.

“I want to place £800 on number five, The Evidence.” He drains his cup again. It’s an absolute constant, a dead cert.

Still feeling flushed after the meeting in the mortuary, I take off my jacket and clutch it to my stomach as I follow DI Bagley into the interview room. Gaby Brock sits at the table holding a plastic beaker. She looks like a battered baby. The forensic suit she’s been dressed in is way too big and she stares out of her swollen face with wide eyes. She seems unaware of our arrival and equally oblivious to the arm around her shoulder. It belongs to the large, sobbing woman beside her. The woman looks up as we sit down opposite. I drop my jacket over the chair.

“Thank you for coming in at this difficult time, Mrs Brock. We’re sorry for your loss. I’m DI Bagley. This is DC Adams.”

“I’m Linda Parry,” the large woman says, “Gaby’s sister-in-law, Carl’s sister.” She swallows hard.

Bagley ignores her. “I need to ask some questions about this morning. Are you up to it, Mrs Brock?”

Gaby Brock blinks her doe eyes.

Bagley seems to take this as a yes and presses on. “Can you tell us what happened?”

Gaby’s pale mouth remains closed for a moment, apparently still frozen by her ordeal. When she finally speaks, her voice is soft and pretty – like honey. It doesn’t seem right for a voice like that to come out of such a damaged face.

“We were asleep in bed,” she says. “Two men burst in and dragged us downstairs. One of them punched me in the face and I fell. The other grabbed my arms and pulled me up again.”

“Can you describe these men?”

She blinks again as if searching the images in her head for the faces of her attackers. “They were black,” she whispers eventually, “and big.”

“How old were they?”

This time her pause is so long that Linda Parry squeezes her shoulder and prompts, “Come on, Gaby, love. You can do it.”

I see Gaby wince. The shoulder squeeze must have hurt. It’s a stark reminder that, although the face pummelling is there for all to see, there are other injuries hidden under the forensic suit.

“Well, Mrs Brock? How old were your attackers? Teenagers? Twenties? Thirties? Older?” Impatience steals into Bagley’s voice.

Gaby’s hand tightens on the empty plastic cup. Somehow she’s managed to consume an entire outpouring from the interview suite coffee machine. The trauma must have affected her taste buds.

Gaby’s answer rolls out at the same hesitant pace as her previous ones. “They weren’t kids, but I don’t know how old.”

Bagley studies the woman’s face, weighing up her reliability as a witness. “What were they wearing?”

“I couldn’t see. It was dark.”

“You mean they didn’t turn the lights on?” she asks, more irritation creeping in.

How long ago did the DI attend the Dealing with the Traumatized Victim course, I wonder. Do they offer refreshers?

Gaby shakes her head slowly. “They shone torches in our faces. And I was too scared to look at them.”

“Did you see their hair? Was it long or short?”

“They wore hats. Woollen ones.”

“Balaclavas?”

“No, I don’t think so, but I couldn’t see. I’m not sure.”

“Did they say anything?”

Gaby Brock blinks again and her sweet voice cracks. “They told Carl to get a chair and chain me to it. One punched me on the shoulder and I fell back into the chair.”

Linda lets out a sigh and tightens her arm around Gaby. I turn away, not wanting to see Gaby Brock flinch again.

DI Bagley ignores Linda once more. “Did you notice any kind of an accent?”

There’s another pause as Gaby considers her answer. “I think one was local and one was sort of West Indian.”

“And they brought the chains with them?”

Gaby’s body tenses as if reliving the memory. “They brought metal chains and handcuffs. They made Carl tighten the chains around me and handcuff my arms to the chair. They gave him the keys and told him to put them in my pocket.” She taps her chest to indicate the spot where her pyjama pocket had been. “Then they took Carl away.” Her words are faint and slow.

Her eyes are watery, empty. Victim’s eyes. Victim … Still living, still breathing but a victim nonetheless … No one could know how that felt except another victim … The hairs on my arms bristle but I won’t go there . I concentrate on the interview.

A thought comes to me but I’m not sure of my role. Does Bagley want me to remain the silent trainee or should I take part in the interview?

“Did they say anything else?” Bagley asks.

Gaby Brock takes a deep breath. “They said to Carl, ‘You need a lesson of your own, teacher’.”

“He was an English teacher at Swan Academy and a damned good one,” Linda explains. She pats Gaby’s hand. “Everyone liked him, even the kids.”

I think of the literature textbooks on the Brocks’ bookcase.

“And the kidnappers definitely called him ‘teacher’?” Bagley asks.

Gaby lowers her head, too weary even to nod. My heart races. Dare I ask my question?