When Klaus and Elijah receive a cryptic invitation to dinner from their mother Esther, who continues to inhabit the body of Harvest girl Cassie, they find themselves preparing for the worst. With the help of a new witch named Lenore, Klaus, Elijah and Hayley attempt to stay one step ahead of Esther, but things quickly take an unexpected turn. While Elijah finds himself reluctantly teaming up with Gia, a newly-turned vampire, Hayley is faced with an enticing proposition about her new status as a Hybrid after a startling encounter with Esther. Finally, Esther reveals a shocking secret about Klaus' childhood and unveils her ultimate plan for her children.

A new fatal drug that endows superhuman strength sweeps through Gotham. While Jim and Harvey investigate, Oswald tells Maroni that he used to work for Fish, and the mob boss brings Jim in to confirm Oswald's story... or die. Meanwhile, Bruce discovers that Wayne Enterprises may have been involved with the manufacture of the drug and sets out to learn the truth.

Sheldon and Raj test whether they could survive a dark-matter research expedition in a salt mine by simulating the conditions in a steam tunnel deep underground. Leonard and Penny seek advice from Howard and Bernadette after they fight about money.

International superstar Pitbull returns to the ballroom and for the first time joins Julianne Hough, Carrie Ann Inaba and Bruno Tonioli as a guest judge MONDAY, OCTOBER 20 (8:00-10:01 p.m., ET) on "Dancing with the Stars". Pitbull will kick-off the night with a steamy performance of his hit single "Fireball" followed by the nine remaining celebrities performing to a mix of his hits and personal favorite songs. Dance styles will include Salsa, Rumba, Foxtrot, Tango and Jazz. At the end of the night, one couple will face elimination.

The battle rounds continue.

Murdoch and legendary lawman Bat Masterson unite to hunt for Butch Cassidy and the Sundance kid.

Carol looks for an apartment with Nathan and Debbie eager to help, each looking for a place far away from their own homes.

A woman from Ichabod Crane's past comes to Sleepy Hollow in the form of an un-dead Weeping Lady, aiming to harm anyone in her path. Katrina and Crane learn unsettling things about each other's pasts. Abbie has some unexpected flirtatious encounters.

When her efforts to save the planet prove hopeless, Hayley decides that she might get more attention if she becomes a blonde. Meanwhile, Stan and Steve go on a mission to find a new home for the Smiths.

To fix a Los Angeles nuclear reactor that's on the verge of a cataclysmic meltdown, Walter and the team must reluctantly enlist the help of a troubled former member.

Jane struggles to keep her unexpected pregnancy from taking over her life, but with her mom Xiomara pressuring her to sue the doctor who accidently inseminated her, and her constant run-ins with the baby's biological father, Rafael, life is anything but normal. To top it off, Michael's jealousy about Jane and Rafael's past leads him to make an unexpected alliance with Petra. Meanwhile, Jane's own father, Rogelio, is insisting on meeting his daughter, but Xiomara wants to keep the secret from Jane a little while longer.

With Ezra and Zeb arguing constantly, a simple errand to the market goes astray when they get in a tussle with stormtroopers and manage to steal a TIE fighter.

Slotter discovers that his son has been thieving. Isabelle trades her services for much needed cash. Kat is a witness to the cold blooded murder of a travelling preacher.

When Richard buys a '65 Chevy Impala, they put their Gas Monkey spin on it. Richard and Aaron score a ?34 Five Window Ford. And later, Richard agrees to cool off the monkeys with new air conditioning, but the Fired Up crew gets hot and bothered about it.

Welcome to one of America's last frontiers: the wild swamplands of Southern Louisiana, a place whose history stretches back to the 17th century. It's the start of the most exciting - and dangerous - time of year for the swampers, the month-long alligator season. During this 30 day window, swampers make most of their annual income culling gators. Troy Landry, a Cajun whose family goes back three generations is on a mission to hunt down his own personal "white whale", the notorious Big Head, a monster gator he's been after for years.

The team targets an eco-terrorist cell seeking a deadly weapon. Liz attempts to lose her guardian. Red resorts to manipulation to pursue a special someone.

When an ice cream vender is shot, evidence leads Beckett and Castle to believe that an unknown second-grader may have vital information about the case. Castle goes undercover at an elementary school to try and identify the second-grader but nothing goes as planned.

When the team learns that someone from its past is targeting one of its own, they desperately search the city. Operational Psychologist, Nate Getz visits Nell to help her through her traumatic experience.

Alan Cumming, Casey Wilson, Joe Perry, Pentatonix

Sarah Paulson, Jim Rash

Suffering from a crisis of confidence, Raf is pushed to the limit when he takes on a very complex specialist operation. Raf doesn't believe he's qualified, but Fletch and the rest of the AAU team agree that he is the best man for the job.

Lisa and Dan attempt to act as peacemakers as they deal with the fallout from Robbie's revelations.

The exams are over, and it is careers advice day for the Form K. However Alife who takes the biggest decision when he decides he cannot go on teaching without his class and quits teaching. Fraser is upset to be losing his best friend. Alfie reveals he has landed a job at the Playstation factory. Gulliver and his class beg him to return to the school.