Dangerous Echoes 2017

A young medium is welcomed into the home of an elderly woman, raising the suspicions of her relatives who ask Polly to investigate. As Clarrie and Sarah are involved in their own crises, Polly decides to tackle the problem on her own but, in the thrill of immersing herself in old friendships, she doesn't realise the dangerous path she is treading...

In whatever order you read her books, Mai Griffin's series of supernatural thrillers, Ghostly Echoes, will grip you.