These Toxic Things by Rachel Howzell Hall

A dead woman's cherished trinkets become pieces to a terrifying puzzle.

Mickie Lambert creates "digital scrapbooks" for clients, ensuring that precious souvenirs aren't forgotten or lost. When her latest client, Nadia Denham, a curio shop owner, dies from an apparent suicide, Mickie honours the old woman's last wish and begins curating her peculiar objects d'art. A music box, a hair clip, a key chain-twelve mementos in all that must have meant so much to Nadia, who collected them on her flea market scavenges across the country.

But these tokens mean a lot to someone else, too. Mickie has been receiving threatening messages to leave Nadia's past alone.

It's becoming a mystery Mickie is driven to solve. Who once owned these odd treasures? How did Nadia really come to possess them? Discovering the truth means crossing paths with a long-dormant serial killer and navigating the secrets of a sinister past. One that might, Mickie fears, be inescapably entwined with her own.