Ballard is annoyed when she finds out that the fact that she had a date with Falsone is around the squad room. Munch has a doctor's appointment and he's not talking about it. Dr. Griscom calls on the homicide unit when he sees a number of deaths that are related by a poison named phosphozine. The FBI steps in on the poisonings and they put MGee in charge of a task force; they consider it an act of domestic terrorism. One of the victims was a priest; two others were his parishioners. Gharty suspects the communion wine. Following this idea, wine bottles are collected from churches around the city. A needle hole is found through one of the corks. A citywide canvassing of all places where wine can be purchased is launched. Gee disagrees with the bureau's policy of keep information from the public. One possible suspect is captured; however, strange as he is, he's not the one. Through an internal leak, the media is alerted and warns the public, sparking chaos. MGee suspects the source of the media leak is his father and Gee doesn't deny it. Further investigations lead to a phosphozine delivery in which one bottle was allegedly damaged and discarded, the delivery driver (whom Bayliss & Sheppard had encountered) is arrested.