Kieren van den Blink

When people start mysteriously dying in Los Angeles, Don and his FBI team are called in by the Public Health Service to determine if it is an act of bio-terrorism. Applying Charlie's knowledge of the mathematics of diseases, they track the virus not only to stop it, but also to find its point of origin. Once they determine who is responsible and why, they are surprised by the suspect’s motive. Meanwhile, Don is surprised to learn that Charlie has been keeping a secret from him. CCH Pounder guest stars.

Coulson and his team are still reeling from a shocking revelation that leaves the team fractured as they must decide what to do with one of their own. Meanwhile, Bobbi and Mack reveal their true allegiance to Hunter, while elsewhere, Ward and Agent 33 embark on a personal mission.

After Martin's Aunt Bonnie (Valerie Mahaffey), a feeble cancer patient and nurse, vanishes for several hours, her concerned husband and adult daughters summon Martin to help find her. Enlisting Samantha's assistance, Martin finds it difficult to be objective when some of the information they uncover suggests that his nurturing and seemingly proper aunt may have a secret lover, an unlawful business and/or a desire to commit suicide. Meanwhile, Jack, who learns that his combative father, Frank (Martin Landau - "Mission Impossible," "Ed Wood"), is in the early stages of Alzheimer's Disease, decides to make amends with him before it's too late.