A Golden Age Gillian Hazeltine classic!
Margaret Kenton is killed in the Silver Moon nightclub, and circumstantial evidence points to Bob O'Neil, the dead woman's fiancé (and as it later turns out, heir). But Gladys Ingham, one-time court reporter who is herself in love with O'Neil, appeals to the detective firm of Bryce and Glace.
Soon the pair discover the dead woman was behind a city-wide blackmail ring, and that O'Neil is only the first in a long line of suspects that includes Gladys Ingham, herself; Joe Palloni, gangster and owner of the Silver Moon; Giovanni Cerra (alias Jumping Jack), a dancer-gigolo; Tommy Tovallo, Palloni's chief "chopper" (killer); a gangland lawyer named Richfield; debutante Allison Martin, daughter of one of the city's wealthy families; a shady bail bondsman named Doobie; and danseuse Violet de Lisle (whose real name is Maud Slade).
When Allison Martin is kidnapped, even the police are stumped and agree with Bryce and Glace that only a man of uncommon gifts can unravel the case, so they call in the extraordinary astrologer and seer, the Persian mystic known as Semi-Dual. Yet, Semi-Dual doesn't just rely on his psychic insights to solve cases; as he says, "Material proof for material man." For he is an expert unearther and reader of clues as well.
When the stars reveal that someone in the underworld has put out a contract on his friends, Bryce and Glace, Semi-Dual realizes he will have to work swiftly if the Ledger of Life is to balance and a ruthless murderer brought to account for his crimes.