Author’s agent: Steven Malk, Writers House. Some unfortunate caricatures-French people portrayed as rude, Soviets yearning for American jeans-may detract from the narrative for some, but goofy, two-color pictures by Lowery (the Doodle Adventures series) ramp up the silliness of this adventure (kids will snicker at the sight of Mac flying home in his tighty-whities), which should snare even the most hesitant readers. Mac’s madcap quest takes him to Paris and Moscow, where he encounters the French president and a KGB officer before returning the stolen British heirloom and the Mona Lisa. When he arrives at the Tower of London, the Queen suddenly appears, surrounded by a dozen corgis, and distills some British historical jargon, including “regicide” (“my least favorite type of ‘cide,’ ” the monarch quips) before outlining the case. After receiving a call from the Queen tasking him with finding missing Crown Jewels, Mac flies to London. The next minute you are a secret agent for the Queen of England,” deadpans a boy named Mac, who narrates Barnett’s ( The Terrible Two) riotous series debut as an adult recalling a 1980s childhood caper, insisting that the story is true.