England's answer to the King Tut madness--the ""Golden Child"" exhibit at London's great Museum--inspires a literate mystery-comedy that begins superbly but soon becomes far too knotty and cutely frazzled. Waring Smith, a junior officer at the Museum and chum of ancient Sir William Simpson (who unearthed the Golden Child tomb in Africa decades ago but now just putters about the Museum), is sent to Russia when the Museum suspects that there may be fakes among its borrowed Golden Child treasures. Indeed, Smith sees all the real Golden goodies in the Kremlin (!) and returns--only to find that Sir Will has been murdered in the Museum library. The clues include lots of silly hieroglyphics, and Smith's assistant sleuths include a professor named Untermensch and a socialist dissident on the Museum staff. Several bright comic moments, a few nicely Wodehousian oddballs, and some museum satire directly relatable to Tut--but Fitzgerald's formula plot is only half hidden behind all those obvious red herrings and all those hard-working verbal grace notes.