Excerpt from The Stranger on the Train by Abbie Taylor, plus links to reviews, author biography & more

Emma felt a jolt of unease. Surely the carriage had been empty before? She searched sharply for whoever it was, just blocked from view by the handrail. Then the person moved again, coming closer to the window, and she saw that it was a woman.

The woman was leaning forward in the aisle, bending cautiously to peer through the glass. She looked older than Emma, closer to her mum's age maybe, blond and well-groomed. She looked sensible. She looked concerned.

She looked . . . normal.

Emma breathed again.

"My baby," she called, trying to smile. She pointed at Ritchie. "My baby's stuck."

The woman pressed her hand to her mouth, a horrified expression on her face. The expression said: What should I do?

"Open the door." Emma pointed her free hand. "Find the alarm and press it."

The woman nodded. She took a step back and began to look up and around the door.

Christ. What a day. Feeling weak, Emma rested her forehead against the window and looked down at Ritchie. He was sitting on the floor, facing away from her, pulling at the zip on his fleece. All she could see was the top of his head. This was such a stupid situation to have ended up in. It was so exhausting, being a mother. You couldn't relax, you couldn't look away, not even for one second. Probably she and the blond woman would laugh about it when the doors were open and Emma had got on and had Ritchie safely back on her knee.

"Bit of a close one," the woman would say, maybe thinking how careless Emma was but being nice about it.

"I know. You'd want eyes in the back of your head." And Emma would smile, then pull Ritchie to her and turn away. Back to it just being the two of them. The way it always was.

She could feel Ritchie on her knee already; his blocky weight, the apple scent of shampoo from his hair. In her head, everything was normal again. So it was a couple of seconds before she realized that the doors of the carriage still hadn't opened.

She frowned, looking up.

At the same moment, the train gave a loud hiss.

Emma's self-control vanished.

"Help!" Wildly, she hammered on the glass. "Please. The train's about to go."

The woman was back at the window, mouthing something. Her lips moved: "Ex. Op. Ex. Op."

"What?"

"Ex. Op."

The woman gestured vigorously, pointing at Emma, then ahead of her, down the tunnel.

"What?" Emma stared in confusion. Violently, she shook her head to let the woman know she didn't understand.

The train gave a second hiss.

And then a lurch.

"No!" Emma gripped Ritchie's harness and screamed, a high scream of terror. "Please. Stop!"

The train pulled ahead of her. Emma began to follow it. She was trotting before she knew it.

"Stop! Stop! Stop!"

A second later, she was running. It was that fast. One second the train was not moving at all, the next it was hurtling straight for the tunnel. Emma was sprinting flat out to keep up with the harness. Her ears were filled with noise. Ahead of her, the barriers bristled with signs saying: Danger! Stop! The signs were rushing towards her but she couldn't stop. She didn't know if her hand was tangled in the harness or if she was just holding tight, but she knew she would not let go. The barriers were in front of her. Oh Jesus. Oh Jesus. Oh Jesus.

Something grabbed at her arm, jerking her to a stop so suddenly that she flew right around in a circle. There was a burning sensation as the harness dragged across her hand, a vicious twist of her finger as the strap caught on it, then was gone. She stumbled, spun further, landed hard on her knees. The noise increased as the train filled the tunnel, a hollow roar surging back at her, an animal howl of pain and anguish and rage.

Excerpted from The Stranger on the Train by Abbie Taylor. Copyright © 2014 by Abbie Taylor. Excerpted by permission of Atria/Emily Bestler Books. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.