A psychology student attempts to cure her sister's crippling psychosis only to expose them both to its origin: an ancient creature intent on claiming their souls.

When an emotionally-fragile young woman takes a job as nanny to two troubled children at a remote summer cottage, she falls in love with the children's father, while becoming enmeshed in the mystery of their estranged mother - with whom, it turns out, the young woman has her own fraught history. As the summer progresses, she begins to suspect that the family has a dark history that they are desperate to keep secret.

Five strangers awaken to find themselves trapped aboard an alien spaceship that seems to be harnessing their terror to power the ship. They begin to understand that these species have been abducting humans for decades and possibly centuries.