S11, E5: It’s Halloween time at The Jeffersonian as the team gets a surprise visit from Lt. Abbie Mills and Ichabod Crane, who have traveled from the spooky town of Sleepy Hollow to help on a murder case of a young woman whose body is found on top of a 18th century military general’s headless body. The new foursome must figure out how to work together to discover who the 200-year-old headless corpse is and how the two murders are linked. Meanwhile, Booth and Brennan come up with the ultimate Halloween pranks to play on each other in the special.