Fringe 2. Sezon 14. Bölüm (The Bishop Revival)

When all of the groom's relatives asphyxiate at a wedding, the Fringe division investigates and quickly ascertain that a human agency is responsible. Walter realizes that the formula for the toxin was based on research conducted by his father, Robert Bischoff, and that the killer isn't stopping with a single test of his lethal concoction.