Sam and Dean investigate a case where the victims' hands and feet have been severed and each have been branded with a strange symbol. While Sam does some research at a local university, Dean heads to one of his favorite places to investigate - the town bar. Dean strikes up a conversation with a local named Lydia, and the two go back to her place. Sam discovers the symbol on the bodies is a sign of Amazon warriors.
Michael saves a man from drowning and learns his identity is a mystery. Meanwhile, Kate discovers a girl she mentors has serious issues that she has failed to notice.
Over Here Astrid gets an unexpected visit from her Alternate, while Peter and Olivia track a killer using a toxin that has yet to be invented. Both universes collide in a case that pushes the boundaries of what is possible.
Percy has his Guardians hold the members of Oversight hostage until Amanda agrees to his demands. If she doesn't, the Guardians will shoot all the members of Oversight and release a deadly gas inside Division that will instantly kill everyone, including Amanda. Nikita is torn between letting the enemy fall and saving the innocent lives inside Division. Meanwhile, Sean is frantic to save his mother from Percy's clutches and turns to Nikita, Michael and Alex for help.
After some of Portland's homeless youth go missing, Nick discovers a black market supplying the Grimm world with human organs. As the investigation continues, Nick and Juliette befriend a pair of homeless siblings, Hanson and Gracie, whose friends have gone missing.
The Sibunas are reeling at Nina's disappearance and must cover for her both at school and to a suspicious Victor and Vera at home, as well as keeping a furious Senkhara at bay. Joy enters her article into the contest, but Mara thinks that her article was entered. Eddie knows that Joy had lied to Mara and tells Jerome. Nina wakes to find herself in an underground cell, and she is not alone... A distressed Fabian goes to tell Mr Sweet everything, but then while Mr Sweet isn't in the office, he hears Nina calling from underneath realizing that Nina is still alive. Patricia tries to be more couply with boyfriend Eddie, which only serves to alarm him. Nina sees Victor Rodenmark Sr.'s ghost. Under pressure, Fabian makes a wrong move at Senet and things look even worse for the Sibunas.
The Sibunas realize they must play the ancient Egyptian game of Senet - and the stakes are high. Joy is still getting a hard time because of Mara, so when Mr Sweet tells her to enter Mara in the blog competition, Joy makes other plans. Trudy is having strange dreams - could her memory be returning? Victor and Vera secretly practice Senet in his office, while the Sibunas meet Jasper who tells them Rufus knows he's been tricked, and he does it soon after the Sibunas find the rules on a mismatched tile on the library floor. Jerome finally makes his move on Mara, only to discover she's still not over Mick. Down in the tunnels, disaster strikes when Nina moves to the wrong square and the floor gives way beneath her.
On the way home with his family, Danny hits a man with his car who is fleeing from a gunman, and his family gets caught in the crossfire when Danny fires his weapon at the gunman. Frank deals with 9/11 guilt from impending loss of a friend whom he worked alongside at Ground Zero.
Moralo Eval brings Cad Bane and Obi-Wan Kenobi disguised as Rako Hardeen to Count Dooku's palace on Serenno. Along with ten other bounty hunters, Kenobi and Bane are placed in The Box, a massive cube filled with deadly challenges, designed by Eval himself to whittle down the galaxy's twelve greatest bounty hunters to an elite team of five to carry out the plan to kidnap Palpatine.
In a future where humans are infected by untested, microscopic robots, a young man with the ability to control the bots helps a government agency control the tech's vicious creations.
A Florida medical examiner takes viewers through puzzling cases while explaining procedures and conclusions.
Spartacus and his men liberate a Roman villa, but its slaves are wary. Oenomaus throws himself into the brutal Pits, and Glaber supports Lucretias prophecies, despite Ilithyias protests.
Reagan wants to secure a spot at a prestigious preschool for Amy and tries to win favor by organizing a charity auction with Ava's help. Elsewhere, Chris and his brother find that they haven't outgrown their competitive ways from childhood.
The Machine gives Reese and Finch the number of a down-and-out man who has been pushed too far, and they're forced to turn to former Person of Interest Zoe Morgan for help.
As Meredith puts Zola to bed and falls asleep, she begins to wonder -- what if her mother had never had Alzheimer's and she'd had loving, supportive parents? The reverberations of a happy Meredith Grey change the world of Seattle Grace as we know it. What if she had never met Derek in that bar and he had never separated from Addison? What if Callie and Owen had become a couple long before she met Arizona? And what if Bailey never evolved from the meek intern she once was?
Cassie enlists the Circle's help when she receives a frightening warning about the witch hunters' return. At the same time, her true feelings for Adam and Jake surface during a birthday party that Ethan decides to throw with the help of Diana. Meanwhile, Faye and Melissa take their inner power to a chilling new level when they try a little of Lee's Devil's Spirit.
ISIS transports a Canadian terrorist by train to Mounties in Canada. Will Nova Scotian terrorists free him? Will the drunk Sterling fulfill his dream of fighting on the roof of a moving train?
Sheriff Forbes delivers some disturbing news to Alaric and Elena about the weapon used in a recent murder. In the Salvatore brothers escalating quest to kill Klaus, Stefan turns to Bonnie and Abby, while Damon reaches out to an old acquaintance for help in setting up an elaborate plan. Intent on a plan of his own, Klaus hosts a strange dinner party, where he reveals another story from his familys violent past until an unexpected guest brings the party to an end. Meanwhile, Caroline is heartbroken when she is unable to stop a tragedy from unfolding.