Zachary Athanasius Poulos, eleven, and tagalong little sister Zoe, four, are a potent one-two combination: from the first chapter, where Zoe dons a pair of boxing gloves (Zach, supposedly, has too much Greek super-power) and knocks out Zach's challenger, Ferdie, to the last chapter, where she insists it's her year to go to school (""I had another birthday"") and, showing the astounded teachers she can read, gets a special dispensation to stay. But there's lots more here than what Zach can put his clever mind to--like small-arms to drive two crooks from the Big Woods--or Zoe can trigger: in a charming if unlikely incident, she accepts the first black man in WW II Cohoes (New York) as a ""couson"" (all the Poulos' cousins being unseen Greeks) and, through Zach's and her machinations, the talented, burly fellow finally lands a job. The Greek aspect may at times seem to hang heavy--but it's when Zach gets to the carnival, with eager Zoe and very little cash, that the Greek connection pays off winningly. (""Turning away from the counter the man tom me softly in Greek exactly which cups to aim at."") ""Being one of ours, as that counterman put it, is an okay deal, I decided."" And when a new youngster arrives in town, where everyone is something (German, French-Canadian, or whatever), she's taken aback that the kids don't accept the answer ""American."" Among the fast-appearing protagonists with ethnic roots, Zach and Zoe have flavor and spirit--worthy of further entanglements.