How better to celebrate a 13th birthday than by following clues to a priceless treasure hidden for more than 2,000 years while being hotly pursued by armed thugs and Black Ops units? Still by far the smartest person in every room she enters, Charlie continues her quest to track down the world's greatest treasures while keeping herself and the fantastically dangerous formula only she knows out of the hands of an increasing number of intelligence agencies and other bad actors. A bit of ancient steganography sends her, with her half brother, Dante, and his partner, Milana, both CIA agents, from Giza to the Acropolis, the Roman Forum and then the Metropolitan Museum of Art--for, at each stop, a new clue or artifact paired to heavy infodumps about the locale's historical and archaeological highlights. Not to mention one or more ambushes with, occasionally, gunfire, one or more high-speed chases (including one in a chariot, which is at least different), and chances for Charlie's overachieving sidekicks each to take out entire squads of gunmen sent by the Israeli Mossad, the Egyptian Mukhabarat, an Egyptian billionaire, and even the CIA. The prize turns out to be worth the kerfuffle, but even though this is only the third episode, the plot is all manufactured action strung together with mechanical predictability. The characterizations are equally facile. Multiracial Charlie is described as having globally diverse racial origins. Rattles along to thrill-a-minute tracks, but the series shows signs of losing steam. (Action adventure. 10-14) Copyright (c) Kirkus Reviews, used with permission.