Bon Voyage. The Beaver Island Mysteries, #6

A retired spy still wants to save the world. Her nerdy houseguest just wants to survive her vacation. International troublemaker Igor Ivanovitch has been a thorn in Irma Abercrombie's newly-retired side all summer-and now he's demanding her help with a mysterious mission. Irma gleefully turns him down, but isn't so sure he's out of her hair for good. After a beloved local turns up dead, Irma and her nerdy sidekick Violet Blackheart end up on opposite paths, and the former spy has to unravel a mystery with limited help.
To her dismay, not only does the murder appear to be linked to a cold case, it might be connected to Igor Ivanovitch, making Irma determined to find out why he's targeting the citizens of Beaver Island again.and who's responsible for hiring him. The stakes have never been higher for Irma and her allies. With the clock racing, Irma and her crew have to foil Igor and his team for good-or die trying.