This is a novel set in Saint Bartholemew’s Catholic church.  The main characters are mice who scurry around foraging for food and trying to avoid detection by Father Murphy and his congregation in fear of “The Great X” (exterminator).  A few careless mice draw attention to their presence and the exterminator is scheduled.  Hildegarde, the Mouse Mistress and leader of the mouse colony, must come up with a plan to save her charges.  The antagonist is Lucretia who is vying to oust Hildegarde and become the next Mouse Mistress.  In a twist, Lucretia is the only mouse who ends up in danger as a result of the exterminator’s visit and it’s up to Hildegarde to save her.  This book about friendship and forgiveness has enough excitement and humorous situations to keep the reader engaged.  The lovely and detailed illustrations are plentiful and enhance the story.  Accelerated Reader classifies this book as targeted for lower elementary readers, but the ATOS level is 4.5.  I do wish that author hadn’t put in a reference to “X-rated DVDs” on page 57 when the mice were looking in a phone book for “exterminator”.  That seemed unnecessary for a lower elementary audience.  Fortunately, it should go over their heads undetected.