A hidden chapter of Camp Redwood is revealed. The survivors help a stranded hitchhiker.

Cruz and Severide suspect foul play when a fire started by an elderly woman turns deadly. Kidd, Foster and Brett create a women’s-only lounge. Firehouse 51 celebrates some good news.

In the black-and-white noir world of his memory, Charlie navigates the seedy underbelly of Philadelphia as Frank has been "diarrhea poisoned," and it's up to Charlie to clean up the mess.

Phil is determined to finally scare Claire on Halloween. Gloria feels self-conscious about her age when someone correctly assumes she is Jay's wife. Mitch and Cam head to the WeHo Halloween Carnival after Lily decides to go to her first Halloween party alone.

It's Halloween and Randy is dealing with his daughter's marijuana problem. Butters gets an unexpected surprise when he visits the Egyptian Artifact exhibit at the Denver Museum.

Jimmy welcomes actress Emilia Clarke, actor Bobby Cannavale, musician Booker T. Jones, and a musical performance by FKA Twigs.