As the city is thrown into chaos by freezing temperatures, Sylvie gets trapped in a life or death situation. Plus, an abandoned baby is found at the Firehouse.
Jane and Maura are called out to the BCU body farm when a murder victim is found buried among the research corpses; Angela keeps secrets from Jane.
A friend from Bull's past enlists his services to help convince a jury that a domestic abuse survivor who shot her husband in his sleep is not guilty of murder, because she feared for her life and the life of her unborn child.