Poisoned Apples by Selene Blackburn
PROLOGUE
"I used to hate apples," said Amy. "My mum put faces on them, and my dad wrote on them."
...
"John!"
"What?" John puffed, half-jogging to where Sherlock stood bent over. Married life was not good for his stamina.
"I think we found our mysterious woman."
John took a step back. The mysterious redhead who'd disappeared off the face of the earth? The one who'd been traveling with some man when she ran off? John couldn't believe their luck! He shook his head and stepped forward, hunching over like Sherlock to see the proof of their good fortune.
"Oh, no." John whispered. The girl-Amy?- was sprawled on the ground, red curls spread around her bloodied face, her eyes closed. She was dead.