Bull helps a grieving mother, Vernice, sue the developers of a computer program that misidentified her son as a criminal, leading him to be fatally shot by the police. Also, Bull and Marissa clash when she considers a job offer from a rival company.

The SVU is called in to help investigate a wave of hate crimes on Christmas Eve. Rollins catches up with an old flame.

In a series of flashbacks, Donald Ressler recalls his actions in the aftermath of Elizabeth Keen's death.