Instruct: Classify Amazon reviews into positive or negative sentiment
Query: An Unexpected Pleasure

Of all her novels, Agatha Christie reportedly felt MYSTREY OF THE BLUE TRAIN was her weakest effort. But artists are not always the best judge of their own work, and while I wouldn't rank this Christie novel quite as highly as some others, I certainly don't consider it among her weaker efforts. A wealthy father's gift of a famous jewel to a headstrong daughter sets murder in motion, and Poriot must unravel a complex plot involving jewel thieves and con-artists to reach one of Christie's more satisfying solutions. Lightweight, perhaps, but no less charming for that.