When their mother passes away, Nicole (Agnes Bruckner) and Annie (Caity Lotz) are forced to return to their childhood home in San Pedro, CA to make arrangements for the funeral. Through their conversations by phone, we learn that neither particularly wants to - Nicole comes first begrudgingly out of a sense of obligation and Annie only after there is no word from Nicole. The funeral comes and goes and with no word from Nicole still, Annie chooses to stay at the home temporarily with her cousin and Nicole's daughter, Eva. When a series of escalating unexplainable events begin to unfold, Annie must unravel the history of the house and its mysteries.
The Pact is admittedly not a new package of material. It mixes and matches elements of many classic and contemporary horror films - a non-traditionally haunted house, a Norman Bates style idea of interior decorating, a psychic somewhat bordering on psychosis and a main character haunted by things beyond ghosts. Though this could have been a total mess, it was held together by Lotz's strong performance (her portrayal of Annie reminds me a mixture of Ellen Ripley and Clarice Starling), very unique cinematography (unusual angles and images abound) and the atmosphere McCarthy managed to create in an otherwise normal LA ranch. Fans of Ti West's films (particularly the Innkeepers) will find this an interesting comparison, though it lacks the humor of West's films. Any fan of horror will find something compelling here though.
However, like many films with a somewhat similar starting premise, the Pact has difficulty balancing what's going on and making it make sense in the broader picture. Once the supernatural begins happening, the initial mystery of Nicole is sent to the back burner. The horror of coming home to a place you don't think of home is lost to a more explicit horror. Annie's psyche stands up remarkably well even in those moments when most of us would totally question our sanity. We don't see those weaker moments often and it detracts from the impact the film could have had.
Overall, the Pact delivers on suspense and chills. Lotz brings us along with Annie regardless if we want to go or not. In the end, while you could say that the plot becomes somewhat predictable, it's so artfully done you won't care. Bonus: the psychic scene is simply genius.