Publisher's Weekly
The stone of the title is a ruby, set in a diamond necklace given by Horace Tabor to his second wife, Baby Doe, after he struck it rich in a Colorado silver mine. Stolen along with a few million dollars worth of other jewels in a robbery 20 years ago, it was never recovered; the cache is of reawakened interest when the only man convicted of the crime is paroled. A host of felons, investigators and gumshoes, including Jacob Lomax, a Denver private eye met before in Death on the Rocks , cluster around the ex-con waiting for leads to the treasure. A few murders, one of which the police charge Lomax with, complicate the investigation before its climax in a harrowing search down an 80-foot shaft in an abandoned mine. While Allegretto has assembled promising tough-guy detective-fiction elements, his hard-boiled prose isn't spare enough, nor is the plot taut enough, to carry through the story's potential.