City of Secrets — Elisabeth Kidd

When Madeleine Malcolm asks detective Devin Grant to find her missing husband, neither trusts the other's motives.  Grant thinks Maddie has other reasons than love for her quest, and she is unaware that Devin is also investigating a plot against the Prince of Wales -- a plot that Teddy Malcolm may be involved in. But their growing attraction begins to outstrip their caution -- and leads them into danger. Historical Romance/Mystery by Elisabeth Kidd; originally published by Warner as Sweet Secrets