Two murders lead NYC detective Nathan Shapiro out of the city and into the country in this mystery from the authors of the "excellent" Mr. and Mrs. North series (The New Yorker).   Nathan Shapiro might be the gloomiest member of Manhattan's finest, but that doesn't stop the dour detective from getting the job done when the going gets tough . . .   Lois Williams of Glenville, Connecticut, is going about her business when she's abruptly asked to bear witness to the signing of a wealthy elderly woman's will. She is just as quickly rushed out, and is disturbed when she learns that Abigail Montfort died less than thirty minutes after her departure.   Lois can't get the strange incident out of her head and confides her suspicions in newspaperman Bob Oliver, who agrees that something strange is afoot. As they investigate a young woman who may have been posing as Abigail Montfort, their search takes them to New York City and into the path of Det. Nathan Shapiro.   While Shapiro doesn't much like leaving Manhattan, a mugging death in town seems to be linked to the old woman's death in the country. Soon, he finds himself chasing leads with the two amateur sleuths--and what they discover is a mystery that belongs on the front page . . .   Murder and Blueberry Pie is the 2nd book in the Nathan Shapiro Mysteries, but you may enjoy reading the series in any order.