The season-ending episode in Season 6 of "Weeds" is titled "Theoretical Love is not Dead," the title taken from a line by one of the characters in the show.
Nancy and her family have been living in Dearborn, MI, where she grew up. She has contacted her old math teacher (Richard Dreyfuss), who generously offers them board and lodging for a few days and now the Botwin family must flee yet again, with baby Stevie. They make plans to fly to Paris, France, and from there to Copenhagen. But now Esteban and his stooge Guillermo have found them, and all seems lost.
The Botwin family makes its way to the Dearborn airport, but with Esteban and Guillermo blocking their way, not much progress is made. Finally, Nancy (star Mary-Louise Parker) agrees to send the rest of her family on the plane, and remains in the airport with her captors, Esteban and Guillermo. They have Nancy and the baby, and are determined to flee the country with their captives. But Nancy has a Plan "C": At some point in the airport terminal, she alerts the police that she is the killer of Pilar Zuazo. That's right, she is willing to take the rap for her son Shane, and confesses to Pilar's murder in full view of the police and the press.
The police take her into custody, and we are left to wonder what will become of this loving family, the Botwins, now that she has taken responsibity for a criminal act she did not commit.
Nancy leads Esteban and Guillermo to a bust that would lead up to the imprisonment of the trio.