Isabel and Watts kept Julie drugged and hidden in a "dollhouse" room (the pink room seen in earlier episodes) for years.
The episode is widely considered a satisfying conclusion to the season. It pivots away from the "True Detective" trope of vast conspiracies and ancient evils. The "monster" of Season 3 was simply human grief, mental illness, and the tragic clumsiness of a cover-up. true detective s03e08 hdtv