Victoria Raschke 
Voices of the Dead Omnibus [EPUB ebook] 

Jo Wiley runs a punk rock teahouse in the heart of the Slovenian capital, tries not to pry too much into her adult son’s life, and keeps her string of friends with benefits on a tight schedule. When one of those friends is found murdered at an ancient Roman ruin, the death pulls Jo into a whole reality of weirdness she never knew existed.