The Mysterious Affair at Styles by Agatha Christie is her debut novel featuring Belgian detective Hercules Poirot. A refugee of war, Poirot has settled in Essex with the help of Lady Emily Inglethorpe. While his friend Hastings is staying at the Inglethorpe home visiting his friend John, who is one of Emily's stepsons, Emily is murdered by poison. Hastings enlists the help of Poirot in apprehending the culprit.
This is actually the first Agatha Christie book I've read since high school when we were assigned Murder on the Orient Express. I don't know why it's taken me so long, but I'm definitely going to read more soon. Hopefully once I get a little more used to Poirot I won't be quite as clueless as Hastings anymore.