"The Call of the Beach" by Donovan Douglas Thiesson - Paperback

At Crescent Lake, what starts as a tranquil summer retreat soon spirals into a nightmare of supernatural terror. Tyler and his sister Alex find themselves drawn to a mysterious rock on the beach, where an enigmatic figure known as the rock man seems to guard a hidden malevolence beneath the lake’s surface.
 
As the days unfold, Tyler notices unsettling changes in Alex. Her once innocent demeanor gives way to something far more sinister, as if the rock’s dark power is seeping into her very soul. The local community, too, appears to be under the thrall of this ancient, otherworldly force, participating in a bizarre ritual with an unsettling purpose.
 
When Tyler’s friend Deb becomes entangled in the malevolent influence, Tyler is thrust into a harrowing predicament. The rock and the lake demand a sacrifice, but the true nature of the choice he must make remains shrouded in mystery. With his sister and his friend both caught in the web of darkness, Tyler faces an agonizing decision with consequences that are both heart-wrenching and inscrutable.
 
Tyler makes his choice but is left grappling with the guilt and horror of that decision, the lake’s dark power forever altering his life.
 
Years later, Tyler returns to Crescent Lake, now a haunted adult living in a cabin overlooking the cursed beach. Here, he remains ensnared by the lake’s enigma, pondering the true nature of sacrifice and waiting for a chance to confront the shadows of his past and find solace—or perhaps a new nightmare—in the depths below.