Poo, pizza and disgusting germs! Why do we poo and how does digestion work? Who was Louis Pasteur and how did he help? Mark arrives at the studio with terrible stomach pains and asks The Shrinkings Scientists to find out what's wrong with him - in their toughest mission yet Dr Sensible, Professor Small and Junior get ready to fly up Mark's nose to investigate.
Canada is about to have a major election. John Oliver enlists Mike Myers, a beaver, and a moose to give voters some advice. Plus, the unpopularity of the Mexican president Enrique Peña Nieto and the habit of American politicians to misquote historical figures.
Mountaineer Joe Brandl and former cop Andrea Lopez survive in Namibia, which is home to dangerous predators, but inner demons seem to cause more trouble.
Riley, Maya, and Lucas deal with the aftermath of what happened in Texas.
When it appears that things are starting to normalize in the settlement, a new problem arises for the Alexandrians.
Olivia is shaken by Lloyd's kiss and Anna realises that Gino's dream means a lot of hard work. Sarah crosses path with a young girl at the abortion clinic, who is later brought to her for help. Elizabeth begins work at Douglas' refuge.
Superfan Kevin Smith and actor Paul Bettany plus Katelyn Nacon (Enid) discuss the episode "JSS" with Chris Hardwick.
Neville Chamberlain visits Downton for dinner, and is drawn into Violet’s plan to save the hospital, with distressing consequences for everyone. Andy finds an unexpected confidante while helping Mr Mason move into Yew Tree Farm, Mary is uncertain if she has met her match, Edith meets Bertie Pelham in London, and Spratt comes to Denker’s aid. Mrs Hughes struggles to keep Carson happy, while Mary thinks secrets are being kept from her.
Laurie and Tom Garvey’s work to rescue lost souls takes a toll on theirs. Laurie seeks to spread the word about the Guilty Remnant’s dangers, while Tom’s infiltration of the cult uncovers a whole new nest of problems.
Grave robbery is depicted in Halloween displays, created by the three remaining teams. Actress Bex Taylor-Klaus helps judge the competition.
After receiving a cryptic warning from Lancelot about Arthur's intentions, Mary Margaret realizes Arthur may be the heroes' biggest threat, but when she is unable to convince David of the danger, she takes matters into her own hands. Meanwhile, Hook's unwavering love for Emma provides a glimmer of hope in her struggle against the unrelenting voice of Rumplestiltskin. In a Camelot flashback, Guinevere senses that Arthur is losing his way, consumed by his obsession with making Excalibur whole, so she sets out with Lancelot on her own quest into the heart of darkness. In Storybrooke, Dark Emma unleashes a secret weapon in the next phase of her plan to find the brave soul she needs to draw Excalibur from the stone.
After enlisting Amy to help her perfect a trick to perform at an upcoming rodeo, Georgie gets pulled away by Lou and Peter who insist she focus on her schoolwork.
Alicia and Lucca work together on a complicated case involving a designer drug dealer. Meanwhile, Eli persuades Alicia and Veronica (Stockard Channing) to participate in a mother-daughter cooking show to help Peter's campaign, but things don't go as planned.
Elizabeth and President Dalton’s administration are met with hostility while trying to deal with the Russian government. Also, Dmitri is kidnapped and interrogated about being a Russian spy.
While Jake and Holt secretly team up to hunt for a serial killer, Amy and Rosa seek revenge for a sexist assignment.
Noah's undying love for Alison leads to serious consequences. Meanwhile, Alison discovers a surprising truth about how to sustain a marriage.
Holly Collins is not only DSS Mike Shepherd's favourite country musician she's also playing in Brokenwood. Unfortunately it turns out to be her final gig. When she is found electrocuted it appears to be a rock'n'roll suicide. But then again it could have been a drunken accident - or, as Mike suspects, it is perhaps something less obvious. With a careless note scrawled in lipstick the only clue, Mike has to set aside his personal interest in the victim and strike the right note with Holly's dysfunctional band members: Slim Fingers, Waylon Strings and Jesse James. But the more he finds out, the more he needs to know and the less he likes what he learns.
Carrie resorts to desperate measures to figure out who is targeting her. The hackers negotiate the transfer of the rest of the documents.
The Belchers are ready for an amazing Halloween! Louise reveals that she has never been scared before and the family sets out to visit a spooky haunted house. When trouble ensues following their visit, the Belchers find themselves in a zany situation more frightening than they bargained for!