In the fall of 1982, a wave of sudden deaths swept through the Chicago area — healthy people collapsing just hours after taking Extra Strength Tylenol. As panic spread, shelves were cleared, public trust shattered, and investigators raced to find out who had poisoned one of America’s most trusted products.

In 1987, a 911 call from a Philadelphia payphone led police to a row house on North Marshall Street—and to horrors they could barely comprehend. Women chained in a basement. Human remains in the freezer. A pot boiling on the stove. At the center of it all was Gary Heidnik, a preacher and self-styled investor whose neighbors thought he was eccentric but harmless. In this episode, we unravel Heidnik’s disturbing childhood, his twisted church, the pit in his basement, and the crimes that made him one of the most notorious killers in American history.

In September 1989, Annamaria Phelps and Daniel Lauer set out on what should have been a short drive. Days later, their car turned up miles off course, and their bodies were discovered in the woods nearby. Their murders added new complexity to the string of Colonial Parkway cases and shifted how investigators viewed the pattern. This episode explores the final couple connected to the parkway, the evolving investigation, and the many theories that have surrounded the case ever since.