An entertaining premise sinks under the leaden weight of amateurish writing. Young Tristan, abandoned as an infant to a monastery, is recruited as a squire by the noble Sir Thomas as the Knights Templar embark on the Third Crusade. Once in the Holy Land, Tristan encounters both honorable duty and savage butchery, as he is thrust into the role of guardian to the Holy Grail. Kings, assassins, knights and a certain archer of Sherwood cross his path, as Tristan reluctantly undertakes a quest that may depend upon the mystery of his parentage. This might have been an amusing, if over-the-top, diversion; alas, from the howling clunker of the opening line, the prose plonks and stutters through a cliché-riddled morass of glaring anachronisms, historical blunders, continuity errors, ham-fisted foreshadowings, irrelevant info-dumps and bizarre neologisms. Derivative set pieces feature wincingly one-dimensional stereotypes, while the mustachio-twirling villain all but kicks kittens in a cartoonish caricature of Evil. The enticing cover and glowing blurbs can’t disguise what reads like an unedited first draft. Skip it. (Historical fiction. 9-13)