The show begins with protagonist Dan pursuing a former CIA operative and Afghanistan veteran who has been off the grid for 30 years in Connecticut. Dan often sees visions of his late wife Abby, suffering from Huntington's disease. Dan lives a seemingly normal life with his daughter Emily and two dogs, Dave and Carol. After a mysterious encounter with a new shop owner, Dan finds him held hostage by his dogs, leading to a shocking turn of events. Meanwhile, FBI assistant director Harold Harper receives a call about agent Dan Chase, sparking emotional turmoil.