Eliza Boom--assistant inventor, junior spy, and full-on fantastic--investigates a case of puppy love in this second book of a chapter book series packed with jokes, doodles, and dear-diary secrets! When Einstein, Eliza's faithful (and furry) lab assistant and best friend (and dog), falls in love with the next door neighbor's dog, Eliza only wants to help smooth the path to happiness for the canine pair. Unfortunately, the new neighbor, Mrs. McNice, seems to have other ideas. In fact, Eliza is convinced that Mrs. McNice isn't as nice as she seems. But one will believe her. Can Eliza invent the perfect gadget to help her reveal the truth? Or is Einstein's budding romance doomed to failed puppy love?