Tenningway House looked different the second time round. It wasn't as imposing as Howard had first thought when he'd been crouching with his grandma in the unruly undergrowth that was the front garden, waiting for all the lights to go out so that they could creep into the house. He'd remembered shuddering then and gripping his shovel for dear life.

It was not as tall – he didn't have to crane his neck very far to see the red brick chimney or the tiny twigs placed by a bird that was roosting there. When they stepped inside, he marvelled at the expanse that was the hallway, a hatstand in the corner, meekly not in anyone's way. A large mirror ran along the wall to the stairs. Eleanor checked her reflection in it, pulling at her straggly hair.

"You look fine," Howard said breezily and swept past to take a look at the rest of the house.

Eleanor showed him a lovely warm kitchen with a marble-topped breakfast bar with coned lampshades hanging from the ceiling, giving the place a modern touch. He saw the fireplace in the maroon-walled living room, accompanied by two huge black L-shaped sofas and pictures of forest landscapes hanging from the walls. Then she led him up the stairs and he saw her shoulders tense again.

"Are you sure Will isn't home?" he asked as they went down a carpeted corridor branching off to different rooms.

"Positive," Eleanor replied. She stopped before a door and inhaled deeply. "This is the bathroom."

Howard glanced inside, hoping for only a peek, but his eyes widened and stayed glued to the scene, unable to pull away.

Red blood stained the white basin, single droplets having raced to the floor and were now drying in small pools on the dark grey tiles. There had been signs of a struggle since the shampoo bottles standing on the ledge of the pristine bathtub had fallen, causing light-blue liquid to ooze out. If Howard looked closely, he saw that the mirror had a small, hairline crack running down the middle, giving his shocked reflection a slight double.

"He smashed my head into the glass," said Elle. "And that's my blood on the sink."

Howard shook his head, feeling a little queasy. He glanced to her cut temple and then back to the bloodied tiles. At least he knew she'd been telling the truth. "I've seen enough."

Nodding grimly, Eleanor led the way out of the room and into another. Howard was hit by a ghastly smell.

"What is that?"

Eleanor didn't reply, only motioned for him to cover his nose with his sleeve, which he did gratefully. There was a pending sense of doom, something that he couldn't place his finger on.

"What is it?" he repeated, voice slightly muffled.

Eleanor chewed her lip. "You know what it is."

And indeed Howard did. He refused to look at the floorboard.

Will's room was smaller than he'd imagined and a lot messier. There were clothes strewn across the room, papers were thrown on the desk and the bedsheets were crumpled into a ball.

"You're sure you didn't move anything?" Howard asked, trying not to breathe too deeply.

Eleanor nodded. She took the key from under the desk like she'd said it would be and opened the drawer. "This was where the journal and the pills were. Nothing else in here, look."

Howard stooped to look. She was right. Nothing else save for some sweet wrappers and a pencil stump, its carbon point snapped off.

"Can I see the pills again?" he asked and she dutifully handed him the fat cylinder. He turned it in his hands, trying to think of what his father would say. Would he be willing to help? Would he accept another call?

Howard decided it was worth a shot. His father was a doctor – if he didn't know anything about it then maybe he could get the expertise of someone who did. He dug for his phone and scrolled through his contacts.

"Howard?" came his father's tired voice.

"Dad—"

"Listen, son. Now's not a good time. I'm right in the middle of a—"

"Dad, this is important. I wouldn't have called you if I didn't think it was."

"Okay, quickly. Ten seconds. Shoot."

Howard glanced at Eleanor. She watched him in earnest, eyes bright. "Do you know of a pill," Howard began slowly, "that can cause temporary memory loss?"

"What do you mean? Well..." His father trailed off in thought. "You've got the drugs like benzodiazepines that help with anxiety and they're associated with dementia. Or you've got antidepressants that—"

"No," Howard cut in sharply. "I'm not talking long term. I mean something that causes immediate memory loss... like 15 minutes after you take it."

There was a slight pause. "Howard, should I be worried?"

"No," replied his son hurriedly. "It's just... Carabella was telling me about it at lunch and I thought you might know more."

"Yeah, well, you know what you're grandma's like."

"So there's nothing?"

"Well, there's nothing on the market."

Howard gripped the phone tighter. "On the market?" he echoed.

"I heard they're trialling memory loss drugs in labs on mice but that was months ago. Aiden told me it was an awful idea and I agree because what if it gets into the wrong hands?"

Howard glanced at Eleanor. "So it exists?"

"Well, uh, yes."

"Thanks," Howard said, pulling the phone from his ear. "I'll leave you to your patients now."

He hung up and Eleanor hounded on him. He retold what his father had said and her face lit up.

"You see?" she cried. "I was right! It all fits!"

Then they heard the front door slam.

"Quick!" Eleanor snapped. She yanked him into the corridor, down a few steps, and into another bedroom. Breathing heavily, she turned the key inside the lock and then visibly sagged against the door.

"Will's home?" Howard asked.

She nodded silently and then padded towards the bed. It had a cream cover and was neatly made with plump blue patterned pillows adorning one end. The whole bedroom screamed Eleanor with its white, cream and blue palette, everything beautifully aligned and placed with intense care and thought. Unlike Will's desk, hers was cleared away save for a gold-sprayed wired pot of stationery and a diary calendar.

"What do we do?" Howard whispered. Eleanor had splayed herself on the bed as though preparing herself to be martyred. "He's going to find the drawer open. And"—he looked down at his hands which clutched the notebook and tub of tablets—"he's going to find these missing."

"Crap," sighed Eleanor.

"At least you locked the door," said Howard, "if that provides any comfort."

"What do you think?" Eleanor rolled to her side. Then, "How do you think he's going to kill us?"

"Strangulation maybe? Like he did to you? Or do you think he'd stab us with one of his needles? Or what about—"

Eleanor waved a hand for him to shut up. He did, glancing nervously at the door. They remained in silence for a few seconds, and Howard could hear Will's heavy breathing as he passed into his room.

Any second now, thought Howard.

Then there came the sound of paper rustling, a quiet growl. And then:

"ELLE!"

Eleanor hid her face into the pillow. Howard held his breath, felt the pulse at his neck, felt his fingers start to tremble. Fists flurried against the door, making Eleanor squeak a little and Howard jump.

"ELLE!" Will roared. The pounding continued. Howard wasn't sure how long the door would hold. "ELEANOR COYLE!"

Eleanor sat up and looked wildly around the room. She gestured to the window frantically. Howard shook his head; they were too far up. If they jumped, they would surely kill themselves.

The blows were harder now and Howard guessed Will had resolved to kick at the door now. He glanced at Eleanor and she started pointedly back.

There was nothing else to be done. They were trapped.

Howard took a step towards the door and, ignoring Eleanor's hurried whispering and tugged at his arm, placed his hand on the wood. He could feel the blows like little shots being fired.

"Will," he said clearly. The pounding continued. "William!"

Howard imagined a moment of confusion as the blows slowed.

"It's Howard," he said.

Another pause. "What?" Will snapped. "Howard, what the fuck are you doing in my house?"

"Listen, I can explain." But as he said it, Howard began to doubt himself. He knew it wasn't possible to reason with a potential psychopath.

"Was it you who went through my things?" Will spat. Howard could hear his ragged, husky breathing as though it were right next to him. "Give me those pills. I need—"

"It was me," said Howard calmly. "I broke into your house and looked through your stuff - I've got them right here. Listen, I'm going to crumble the pills to a powder and sprinkle them out of the window and watch them blow in the wind. Is that what you want?"

Will stayed silent. It was as though he was waiting for a cue, a sign, a prompt.

"I know what you did, Will," Howard said eventually. "The proof is all here. It's as clear as day. You killed Jonathan Coyle and you staged Elle."

Will inhaled sharply, his breath hitching in his throat. Behind him, Howard heard his sister do the same. Outside, in a tree, a bird tweeted.

"I didn't mean it," came the whimper. "Howard—"

"I don't want your pleas, Will. I want the truth coming from your own mouth. We'll deal with the sentiment later."

Howard thought he heard Will sigh.

"If I tell you, you let me have those pills back."

"So you can take all three? Forget it all happened? Die of an overdose?" Howard ventured. "Because I know that's what you'll do. That's why I'm going to destroy them, Will. Your life is too precious to take away."

"Howard, please."

"Confess to me."

A pause. There was no reply.

Howard made his voice colder, harder. "Confess, William. Now."

Another sigh, so faint that Howard had to strain to hear it.

"Okay," said Will eventually. "Okay."