Meredith dreams of what her life would have been if her mother had been healthy.
While vacationing in Mexico, Lightman and Emily become involved in the case of a missing American woman; Foster investigates tainted blood in local hospitals.
Jane and Maura investigate a family's background when a man is killed; Jane suspects that Maura is hiding something.
A desperate man turns to Allison for help when his wife disappears; Allison and Joe worry when Marie breaks down during a test.