After being embarrassed over wearing a childish costume at a high school Halloween costume party and being ignored by the guys, Sue asks a flabbergasted Mike for his advice on what boys want when it comes to girls. Meanwhile, Frankie reluctantly volunteers to take Brick’s socially awkward school social skills group trick-or-treating, and Axl and his friends devise a plan to trick rather than treat the neighborhood kids on Halloween.
Castle and Beckett confront the possibility of paranormal foul play when a world renowned ghost hunter is mysteriously murdered while investigating a haunting at a legendary New York mansion.
The gang begins to realize their romantic partner reminds them of one of their parents. Meanwhile, Barney and Nora’s planned romantic evening is ruined by a string of bad events.
When Alicia’s key witness commits suicide, she must turn to the only person whose testimony can salvage her case. Eli makes big moves on Peter’s behalf.
The political powers that be make big plans for national hero Brody, but his increasingly erratic behavior threatens his media darling status; Carrie grows desperate for evidence linking Brody with Abu Nazir, as Saul directs her to focus on Nazir’s money trail.
The CBI team investigates the murder of a woman whose corpse washed up on an island off the coast of California. Rigsby worries that his relationship with a public defender will create awkwardness between him and Van Pelt.
Phil takes Haley to visit his alma mater. Claire goes out with Mitchell and Cameron. Gloria and Jay may have to broach a delicate subject with Manny.
As the Heck home begins to literally fall apart, Frankie and Mike consider leaving homeownership behind and moving the family to an apartment. Meanwhile, Axl tries to fake Frankie out by pretending that he’s sick in order to get out of taking a school test – and must later convince her that he’s well enough to attend a party that evening; Sue and her ex-sort-of-boyfriend, Brad, volunteer to prepare a school skit about showing the dangers of texting and drinking while driving; and Brick tries to offer a little bit of levity by spouting off Shakespearian quotes.
Castle and Beckett work a murder case around the theft of a valuable sculpture. Serena Kaye, a smart, sexy insurance investigator, joins Castle and Beckett in the investigation, but she also has her eyes set on Castle, all the while hiding a very important secret from the team.
When Ted goes on a date without researching the girl on the Internet, the gang interferes, showing Kevin that they are too into each other’s business. Meanwhile, Lily and Marshall come to terms with finding out the sex of their baby.