Oldest Sin

This third mystery featuring food critic Sophie Greenway is disappointing after stronger titles like This Little Piggy Went to Murder. Although both the amusing opening poem and the closing recipes point to gluttony as the oldest sin, the focus is really on the power-hungry Church of the Firstborn. Maybe Hart is too close to her subject (her dedication is in part for ""all those long-ago friends who survived their membership in the Worldwide Church of God""), but she loses track of the requirements of the genre. The plot is convoluted, the characters hastily sketched and the solution to the ""mystery"" is unfortunately obvious early on. Hart has done, and no doubt will do, better. (Dec.)