Mabel's incident on the subway leads her to gain help from an unlikely ally. Their journey takes them to a legendary amusement park which turns out to be full of terror -- while amusements and evidence reside back in the Arconia with Charles and Oliver.

Closing in on the killer, Mabel takes her investigative talents into the ring. Oliver and Charles duke it out over a birdcage only to end up confronting their deepest paternal struggles.