"What I seek is the truth. Always the truth."

At a Halloween party, a thirteen-year-old girl named Joyce proudly claims to have witnessed a murder. And while no one believes her, she disappears. After hours, she is found: still in the house, drowned... in a bucket of apples.

That same night, Hercules Poirot is called upon to solve the case, but his mission is not simple, as no one can imagine the reason why the little fairy tale girl was murdered.

And what if Joyce was right? And if she really saw a murder with her own eyes? And if the murderer is... a double murderer?