The train rocked gently as it sped through the night, the rhythmic clicking of the wheels lulling the passengers into a drowsy state.

Among them was Samantha, a young woman on her way home from a long day at work. She yawned and stretched her arms above her head, the strap of her top slipping down to reveal the smooth expanse of her shoulders.

As the train made a turn, she felt a large, warm hand come to rest on her bare skin. She started, eyes flying open in surprise. Turning her head, she ...