The Silence Architect. The Memory Collector, #2

Beatrice Wren cannot recognise faces. She's hidden this all her life, navigating Victorian London through observation of clothing and mannerisms, and the whispered memories of objects. Only one person's face has ever been clear to her: Grim's, a scarred locksmith and criminal who is using her for her connections. Now fugitives together, they hunt the man who murdered her twin sister and sent Grim's comrades to die with rifles designed to fail - her own brother.
But their investigation pulls them somewhere else entirely. And her sister's dying message - he wears faces - makes no sense at all. Until it does. Beatrice, who can't distinguish friend from foe, must identify the killer before she, too, disappears like so many before her.______A dark psychological thriller about memory, madness, and the price of being different. For readers of Sarah Waters's Affinity, Michel Faber's The Crimson Petal and the White, and Diane Setterfield's The Thirteenth Tale.