A psychiatrist interviews Gacy; Tovar and Kozenczak uncover systemic failures; teenage love unfolds.

In the past, Gacy confesses to Sam how he groomed, sexually assaulted and killed boys and young men.

After a teenager disappears, officers track, interrogate and tail the man he was last seen with.

Officers excavate the crawl space beneath Gacy's home; Gacy shows where he disposed of Rob's body.

Tovar drives Gacy to court hoping to uncover his kill count; Gacy's grooming of Cram is revealed.

As police make a shocking discovery, the media circus begins; two teens navigate boyhood in Uptown.

A blizzard buries Chicago; Kozenczak tracks down Gacy's surviving victims; a teen learns sex work.

Jeffrey Rignall's story is told; Gacy's execution day brings protests, reunions and moral debates.