An ancient evil in Anne's head aims to ruin her tranquil life and end humanity.

It must be Tuesday.

A house of her own with a white picket fence, complete with a loving partner, Anne Perrin finally has the life of her dreams — including the job she always wanted and a caring family to share it all with.

But every Eden has its Pandora's Box. Anne's personal heaven is marred by a malevolent presence in her head who, if given a choice, would use her to usher in a dark age, ending humanity as she knows it. The only thing holding it at bay is an unpredictable computer implant in her chest that seems to have its own agenda.

Two unexpected visitors turn Anne's delicate world upside down in completely different ways — one better than she could have ever hoped, one catastrophically terrible — pitting Anne in a nightmare battle against the very people she holds dearest: her family.