Hercule Poirot, a charming and quirky retired Belgian police chief, is asked by his friend Hastings to assist in the unravelling of a confusing turn of events. An elderly, wealthy lady has been murdered; the suspects: her new husband, spiteful family, or long-time companion. The solution: one that nobody was expecting. Follow the unofficial detective and his friend as they tear apart the details of this murder at the Styles Estate in a race against the unknown murderer and the English court of law.
I would recommend The Mysterious Affair at Styles by Agatha Christie for ages 16+. This book is a classic whodunit complete with bumbling police chiefs, nighttime murders, dapper detectives, and family intrigue. There are a few mature details to watch out for, including some minor profanity; overall, a well-written and attention-grabbing mystery. 4 out of 5 stars.