The Pazzis prepare a murderous plot for Easter Sunday. The Turk tells Leonardo where to find the Book of Leaves. Lucrezia makes a confession as Leonardo attempts to save the Medicis.

Leonardo builds an underwater suit and uses the sewers to enter the Vatican, where he meets the Pope and the mysterious prisoner. Giuliano reveals the true identity of Rome’s spy.

A clue from the Turk about the Book of Leaves sends Leonardo to Wallachia, where he encounters Vlad Dracula. Lorenzo and Piero meet the Duke of Urbino. The search for the true spy continues.

Lorenzo orders Piero da Vinci to defend his estranged son in court. During a performance for visiting royalty, Leonardo surprises the corrupt judge. Back at his workshop, Leonardo is surprised by the Turk.

Bechhi is accused of being a spy for Rome. The armies of Rome and Florence face off, and Leonardo reveals his latest weapon.

Riario engages the Pope and a mysterious prisoner in a discussion concerning the count’s defeat, while Leonardo searches for a rational explanation when an outbreak of demonic possession occurs at a convent, and the blame is placed on the Medicis.

Leonardo continues his quest for the Book of Leaves. The Pope’s nephew arrives and meets his spy. Leonardo’s war designs fail, causing a rift with the Medicis. The Pope learns of Leonardo’s prowess.

Rising artisan Leonardo da Vinci is commissioned by the powerful Medici to create an Easter spectacle in Florence. After some maneuvering, da Vinci is hired to engineer war machines. A mysterious Turk intrigues Leonardo.

It’s the tenth anniversary of “Arrival Day” and the town is preparing a commemoration for the fallen soldiers. Gloria selects a small group of human teenagers who will spend some time inside the sector to see what it’s like to be an Atrian for a day. In addition, Gloria assigns Emery the task of filming the interactions. While Grayson offers to help her with the project, Roman strongly objects to Emery going inside the sector. Despite Roman’s concern for her safety, Emery decides to move forward with the project. While Sophia is excited to show everyone around her pod, Teri and Drake resent the intrusion and decide to have a little fun at the humans’ expense. However, when Drake is kidnapped during the tour, he’s surprised by who is behind the abduction. Meanwhile, Julia confronts Roman with her suspicions about cyper.

Roman and Sophia prepare for a funeral. Roman is surprised and suspicious when his Uncle Castor shows up in the sector offering to help the family. Meanwhile, Emery tries to talk to Roman about what happened, but he doesn’t want anything to do with her. Upset, Emery turns to Grayson. Meanwhile, the Atrian Seven are invited to the school carnival. However, the fun ends after Drake is kidnapped and Roman finds out the Trags are preparing a hit on Emery and her family at the carnival.

When Emery Whitehill was 6 years old, an alien spacecraft crash-landed in her small town and she met Roman, a 6-year old Atrian boy, who sought refuge with her before being taken away by the authorities. Ten years later, the two are reunited as the first group of Atrian teens is about to enroll in high school in a widely scrutinized social experiment to see if humans and Atrians can live in peace. Both Emery and Roman are surprised at the small-mindedness of their respective communities. Roman’s sister, Sophia, is excited to make new friends, but their fellow Atrians, Teri and Drake, openly distrust all humans. The human students are equally wary of the aliens, especially the school’s queen bee Taylor. Kind-hearted Grayson is drawn to Emery but has a secret that could threaten their new friendship. Only two of Emery’s friends – Julia and Lukas, seem able to accept the Atrians. Emery and Roman find themselves drawn together again but outside forces work hard to keep them apart.

Things grow increasingly tense between Carrie and Tom. When Larissa drops an unexpected bomb on Carrie, Sebastian decides he, too, needs to come clean about something. Maggie turns to Walt when she thinks Pete is cheating on her, but gets the surprise of her life. Mouse and West find themselves in a sticky situation. Elsewhere, Samantha considers leaving the city, and Larissa’s wedding to Harlan is out of this world.

Carrie, Mouse, Maggie, and Walt decide to go to their senior prom – at The Waldorf Astoria – together for a final hurrah. Larissa offers Carrie an opportunity that makes her rethink her plans for the next year. Mouse learns a secret about Donna LaDonna that could threaten her reign as queen bee. Meanwhile, Sebastian hides a big decision from Carrie.

When Bennet starts slacking at work, Carrie tries to cover for him. However, when Larissa finds out, things backfire big time for them both. Samantha makes an uncharacteristic decision about her latest fling. Sebastian’s father asks him for a favor that could change Sebastian’s future forever. Meanwhile, Tom is hoodwinked by another – beautiful – lawyer when negotiating a deal, and is advised by the person he least expects.

Walt and Bennet get some devastating news that forever changes their future. Sebastian gets an exciting work opportunity, causing him to bail on Carrie on Valentine’s Day, much to her chagrin. When Maggie accidentally enlists in the army, a surprising duo comes to her rescue. Elsewhere, Tom uses some reverse psychology to encourage Dorrit to start dating again.

Larissa gives Carrie some harsh advice about her relationship with Sebastian. When Harlan asks Tom to work overnight on a top-secret case, Dorrit decides to throw an impromptu get-together, which quickly spirals out of control. Meanwhile, Mouse and Donna get surprisingly close and Sebastian makes a hasty decision after another fight with his parents.

Carrie is delighted when she gets the chance to interview the CEO of Bongo Jeans – but the pressure is on when Larissa tells Carrie that this is her last chance to land a piece in Interview magazine. Mouse gets some news that drives an unexpected wedge between her and West, and Sebastian’s father delivers other news that could forever change Sebastian and Carrie’s relationship. Elsewhere, Walt finds a surprising father figure in Tom, and Maggie tries to muster the courage to tell her dad the truth about the last few months.

Carrie is shocked when she reads a nasty rumor about her in a New York City gossip rag, but Samantha has a plan to set the record straight. Walt steps in when Bennet feels taken advantage of at Interview. Mouse, worried that she and boyfriend West are stuck in a rut, does something very risqué. Meanwhile, when Maggie experiences a medical emergency, Sebastian is forced to reach out to the one person who can help.

When Carrie struggles with writer’s block, Weaver tries to help but gets in the way. Maggie and Sebastian grow closer after learning some shocking news. When Bennet moves to a dangerous neighborhood, Walt takes drastic measures to keep himself safe, with both hilarious and heartfelt results. Meanwhile, Larissa and Samantha finally find some common ground: sex.

When Sebastian learns that his mother is getting remarried, he asks for Carrie’s dad to make sure she is legally protected. Carrie is furious when she discovers that Weaver has secretly read her journal. Mouse volunteers to help with the Homecoming float, but tries to distance herself when West wins Homecoming King. Samantha finds herself a place to live and another unusual job. Meanwhile, Dorrit begins to feel smothered by Miller, especially when he befriends her dad, and Donna LaDonna gives Dorrit some wise advice.

Carrie is happy going to her junior prom, but when hidden secrets are revealed plans begin to change. Dorrit is determined to take her relationship with Miller to the next level, but things hit a bump along the way. For the first time in her life, Mouse decides to defy her parents to date whom she wants. Tom begins to struggle with sneaking around, especially when he thinks someone might be on to him. Elsewhere, Larissa makes Carrie and Walt an enticing offer.

When Carrie inadvertently complicates things with Sebastian, she tries to fix it by taking him to Madonna’s “The Virgin Tour” launch party – but in her quest for the perfect night, only makes things worse. Despite Mouse’s best efforts to avoid West, she can’t seem to deny the romantic sparks flying between them. Dorrit turns to Donna LaDonna for advice about her budding love life. Meanwhile, Tom has an awkward encounter when he spends the night somewhere new.

Carrie jumps at the chance to a take on a fabulous new identity as Larissa, but gets more than she bargained for when Larissa’s hijinks catch up with her. After a whirlwind day in Manhattan, Walt is forced to face the feelings he is desperately trying to hide. Sebastian and Maggie agree to keep a secret from Carrie. Mouse takes a page from Donna LaDonna’s playbook. Meanwhile, Tom decides to take a meditation class, but finds himself surprisingly tense after a run-in with another attendee.

On her seventeenth birthday, Carrie torn between an opportunity to mingle with New York’s literati and spending time with her friends and Sebastian. Mouse goes to extensive lengths to impress a Harvard alum who has her eyes set on West, with hilarious results. Walt starts taking responsibility for his previous actions. Elsewhere, Dorrit’s search for the perfect gift for Carrie lands her in a sticky situation with romantic possibilities.

When Dorrit goes missing under Carrie’s watch, Carrie lashes out at Sebastian, the one person who can help her find Dorrit. Mouse butts heads with West, a popular jock who, much to her chagrin, stole her spot as number one in the class. Walt surprises himself when he confides in someone completely unexpected. Meanwhile, Tom finds himself in uncharted territory when it comes to women and turns to Larissa for advice.

Carrie is thrilled when the junior-senior lock-in provides the perfect cover for a night out in Manhattan with Larissa and her Interview co-workers – until a surprising encounter turns her night upside down. Maggie and Mouse confront Sebastian about his feelings for Carrie and tell him he better make a grand gesture if he stands any chance of winning her back. Harlan finally convinces Tom to go on a double date, with surprising results. Meanwhile, Maggie tries to find the courage to tell Walt about Simon before Donna LaDonna does.