Optimum Dose (The Dreadmoor Cycle)

Stranded in Thailand with no money or passport, Isla takes a temporary job on a private island, hoping for a chance at a fresh start. However, as she settles into her new environment, unsettling issues arise—her door won't lock, surveillance feels invasive, and the island's past remains shrouded in silence. With a week until rescue, Isla must navigate the mystery and danger lurking in her isolated surroundings.