The Shadow Palace - Jane Steen

For unwed mother Nell Lillington, 1876 Chicago--and her new wealth--offer the promise of longed-for independence. She dreams of a place in society for her daughter Sarah and contentment for her friend Tess. Yet how can she settle in a town where she's far too likely to run into Martin Rutherford and his glittering, faithless wife, Lucetta? Can she resist her love for Martin for Sarah's sake?

Martin was doubtless joking when he told Nell that if she got herself mixed up with a murderer for the third time, he'd disown her. But when Martin himself is arrested for murder, Nell's dreams appear to be swallowed up in the new web of secrets she constructs to help him. Secrets that threaten to alienate Tess, Sarah, and even Martin . . .

The third book in the House of Closed Doors series will take you to a Chicago teeming with opportunistic new Americans, luxury-loving merchant princes and hard-hearted denizens of the underworld.