We gave it a C
You might assume that mixing a hooker, a lingerie model, a rich old man (said Mr. Paradise), and some mean-as-snakes murderers would get you at least a semi-interesting story, especially in the vaunted hands of Leonard. But what your mother always warned you about the word assume is applicable here; this is a flaccid nonmystery that seems amateurish even for a first-time author. Luckily, with 38 books preceding this one, there’s enough old Leonard to go around until his next effort, which we (dare we say it?) assume will be better.