Breathe In, Bleed Out by Brian McAuley

It's a Midsommar night's Scream in this blood-soaked thriller set at a remote healing retreat from horror author Brian McAuley.

Hannah has been running from her demons ever since she emerged from a harrowing wilderness trip without her fiance. No one knows exactly what happened the day Ben died, and Hannah would like to keep it that way... even if his ghost still haunts her with vivid waking nightmares that are ruining her life. So when her friend group gets an exclusive invitation to a restorative spiritual retreat in Joshua Tree, Hannah reluctantly agrees in search of a fresh start.

Despite her skepticism of the strange Guru Pax and his belief in the supernatural world, Hannah soon finds healing through all the yoga, sound baths, and hot springs offered at the tech-free haven. But this peaceful journey of self-discovery quickly descends into a violent fight for self-preservation when a mysterious killer starts picking off retreat attendees in increasingly gruesome ways. As the body count rises and Hannah's sanity frays, she'll have to confront her dark past and uncover the true nature of a ruthless monster hellbent on killing her vibe for good.