A PHOENIX COLD CASE: David Mapstone has returned to Phoenix, Arizona, the desert city he left behind a lifetime ago. The ex-cop, ex-history professor is working the police dept''s cold case desk, unearthing long-buried secrets. And he''s good at it: as an ex-historian Mapstone knows the past is never past, as an ex-cop he knows he can''t trust anybody...

CACTUS HEART: Phoenix, a city built on the bones of its past, has just given up one of her longest-kept secrets. Walled up in a tunnel beneath an abandoned warehouse, the skeletons of two four-year-old twins are discovered, the victims in a notorious kidnapping case from the 1940s. But what starts as a tying-up-loose-ends case for David Mapstone quickly becomes something far more sinister.

As Mapstone delves further into the evidence, he discovers a complex web of secrets, lies, money and power. But with a very contemporary killer on the loose, he must untangle the truth – and fast – before they strike again...