The Library
The Library

"What kind of magical, world-ending apocalypse could possibly happen at a cheesy high school science fair?"
Eve Baird

"And the Rule of Three"[1] is the seventh episode of the first season of The Librarians. It aired on January 11, 2015 as the first part of a two-hour event.[2]


When a group of hyper-competitive high-school students start undercutting each other with witchcraft, the Librarians have to intercede before disaster destroys them all.[2]


A student named Jonah Gordon is getting ready for school and preparing a presentation for a science fair when his dad asks if he's ready to go. As he replies, his body begins to freeze, and soon he's entirely unable to move.

Eve arrives at the Annex on a day off and is surprised to discover Jenkins, Jacob, and Cassandra all there as well, working on their own projects. It isn't long before Ezekiel appears as well, running through the back door with a package clutched in his arms and sirens and flashing lights in the background. Luckily for him, the clippings book grabs everyone's attention by levitating and glowing. When Eve asks Jenkins if it's ever done that before, he says no, and that it must be a magical threat of epic proportions. However, what appears in the book is a poster for the Chicagoland STEM Fair, sponsored by the McCabe Learning Foundation. Cassandra is extremely excited to hear about the STEM Fair, which she explains is a science fair dedicated to Science, Technology, Engineering, and Mathematics.

The Librarians travel to the high school hosting the event, with Cassandra still excitedly talking about the cutting edge developments there. Eve is doubtful that any kind of serious threat could be at found at a high school science fair, but changes her mind when they walk into the auditorium and realize that the STEM fair is much bigger than they'd expected. Cassandra explains that they're highly competitive events. On stage, the superintendent introduces the president of the McCabe Learning Foundation, Lucinda McCabe, who explains that the winners of the fair can receive not only full college scholarships, but also internships and research grants.

After her speech, Lucinda McCabe introduces herself to the Librarians, and when she hears that they're Librarians, she believes they must be the judges from the county library. This gives the Librarians a chance to explore the fair, looking for anything magical or unusual that could have set off the clippings book. While Cassandra is enthusiastic about the experiments and studies, the others are more baffled and bored. Eve finally gets excited when a student, Leonard Cole, has a baking soda volcano--something she'd been reminiscing about earlier--and gives him a pep talk when he says he's not even supposed to be there.

Meanwhile, Cassandra tells Ezekiel that she'd been one of the science fair kids when she was younger, and that she'd had a whole wall of trophies. They see a trio of goth kids heckling the science kids, and when Cassandra says that goths and geeks should be friends, Ezekiel counters that high school is like prison, where "you find a crew to run with and keep all the other crews down". Ezekiel plays with a Newton's cradle that's set up nearby, but the first ball doesn't drop back down--it points straight out.

At Leonard's display, he starts up his volcano, which suddenly erupts for real, spewing fire and magma into the air.

Lucinda calms down the public by saying that a student had mixed his chemicals wrong, while Eve and Jacob take Leonard aside to ask him what happened. Eve's attempt to play good cop just results in an overwhelmed Leonard revealing that he has a crush on her. Jacob takes over and finds out that Leonard doesn't even like science fairs, but had entered when his dad had pushed him into it. He'd been fifth alternate, but the students ahead of him had "a bunch of freaky stuff" happen to them.

The Librarians realize that Leonard isn't behind the magic, but someone else at the fair must be. Unfortunately, that leaves a lot of options--all the contestants and spectators are suspects. Ezekiel leads Cassandra to the Newton's cradle he found earlier and says that it's magic, and they're shocked when Jenkins appears and says that it's unlikely. He points out that he has free will and can leave the Annex at any time he wants, and that he's a scientist of sorts himself. Ezekiel demonstrates the weird behaviour of the Newton's cradle, which leads Jenkins to realize that magic is "rewriting local reality". He surmises that the power in play couldn't come from one amateur magic user, and tells them to look for a coven--a group of magic users working together, in a pattern of three.

Cassandra notices the trio of goths from earlier behaving in a suspicious manner. While Eve and Jacob try to track down the goths, Jenkins explains how magic works to Cassandra and Ezekiel: power, focus, and effect. They realize that the goths had been interested in one specific girl, Amy Meyer, a science fair contestant with an overbearing mother. When they head to her booth, however, it's only her mother there. Meanwhile, Eve and Jacob find the goths and Amy--although they're not performing a spell. Instead, one of the goths, Dashell, is trying to woo Amy with poetry set to music provided by his friends. Amy turns him down, saying that her schooling has to take priority, and flees when he asks if she'll at least consider prom.

Back in the fair, Cassandra and Ezekiel try to ask around about Amy, but the first student they ask coughs up an entire swarm of insects. Once again, Lucinda has an explanation for the general public and says that if they cancel the fair, all the students' projects will be forfeited and the students will be disqualified from the scholarship competition. Amy's mother suggests they just give her the prize, as everyone knows she'll win anyway. Instead, the fair is allowed to continue. Lucinda checks in with Ezekiel and Cassandra, and when they mention the unusual events, she says it's like there's a curse on the fair. Cassandra realizes that it's not someone trying to use magic to win, but to make everyone else lose.

When they mention this to Jenkins, he tells them about the "Rule of Three"--whatever magic you do comes back to you, amplified threefold. Whoever is trying to use malicious magic against the other competitors is going to be hit with a fatal backlash. He gives them a magic detecting device, built from the Newton's cradle, and tells them to find the focus of the spell, likely either an artifact or a spell. Eve says that they need to figure out who's using the focus, and trace it backwards from there, and suggests they gather intel from someone who isn't involved in the fair. Jacob tracks down Dashell, sitting in the science lab at the school, and after quoting Lord Byron at him, has a heart-to-heart with him about how the roles people take on in high school are just costumes people put on. He tells Dashell that he wore his costume too well for too long, and that if Dashell likes Amy, he shouldn't let their costumes stand in the way.

Having gotten a full scoop on the entire high school science fair politics, Jacob tells Eve that the one thing everyone has in common is that they all hate Amy. The team finds Amy and her mother at her booth and learn that Amy has been winning fairs since first grade. Her mother is very aggressive, referring to herself as "the Wolverine of mothers", and says that hobbies and a social life are just distractions. Using the magic detector, Ezekiel discovers that it's reacting to Amy's phone and steals it while the others distract Amy and her mother. They realize that there's an app on the phone called "Advanced Learning Buddy" that is a wish-fulfillment spell, disguised as a brain-training program, and that it's too powerful for Amy to have created it. Ezekiel realizes that Amy has never opened the app--someone else must be using it.

Cassandra talks to Amy about the app, and learns that Amy's mother is the one who downloaded the app for her. Amy didn't use the app because it felt wrong, but also because she didn't want to be smarter, she wanted to not have her intelligence be the only thing that defined her. Cassandra explains she was like that in the past, but could not live up to the dream her parents had for her. Afterwards, Cassandra talks to Ezekiel and he asks where her trophies went. She explains that her parents destroyed them as they believed the trophies would be a painful reminder of the past.

While searching for the room with the trophies, Lucinda stumbles through the back door and into the Annex, startling Jenkins.

Through Ezekiel's research, the Librarians discover there are 27 active users of the magical app at the fair. Cassandra realizes that it is three times three times three, meaning any backlash will be multiplied exponentially, and with everyone using it against each other, it's creating a magical feedback loop. Eve is called away by Jenkins, and tells the others to make sure that the kids don't destroy the school.

Back in the Annex, Eve finds Lucinda looking through the Annex's bookshelves and attempts to cover for the Library. However, when Lucinda casually uses magic to split the table, Jenkins introduces her for who she really is: Morgan Le Fay, the sister of King Arthur and a powerful magic user. She realizes that Eve is a Guardian, and calls Jenkins "Galeas", before finding Amy's phone and taking credit for the app. She warns them that the backlash from the feedback loop is going to start soon. Jenkins tells Eve to shoot Morgan, calling her "one of the most evil creatures", before Morgan magically stops him from speaking. Eve attempts to shoot her, but Morgan easily stops the bullets in mid-air. When Morgan slips away through the door, Jenkins tells Eve to get her, no matter the cost.

Eve rejoins the others and starts to tell them about Morgan, when she interrupts them and explains that she isn't actually the one hurting anyone: she simply put the spell into the app and let everyone else use it against each other. When the backlash kicks in, she can use the magic in it to recharge her own powers and stay young. Before the Librarians can do anything, she vanishes, but Eve knows she has to still be in the area if she wants to use the backlash. Eve and Ezekiel start searching for her, while Cassandra and Jacob realize that they need to build a magical Farraday cage to protect everyone. When Jacob says they don't have time to do that, Cassandra says that someone already has--Amy's booth was designed to protect her from magic, because Morgan needed her to stay in the fair to attract hostility. The table at the booth has a pentagram built out of the legs, and Cassandra determines that they can use the legs, amplified by the wish app, to create a magical barrier that will protect everyone. Amy volunteers to help the Librarians, who need an extra person to hold the fifth leg. Her mother objects, but Amy stands up for herself, telling her mother that it's Amy, not her mother, who gets to decide what happens in Amy's life.

As Ezekiel gathers phones with the app on it, Jacob uses his background in surveying to map out the pentagram, and Amy and Cassandra work on dismantling the table, Eve tracks down Morgan and shocks her by punching her in the face. Morgan is stunned, and Eve explains that she used Morgan's own wish-fulfillment spell to give her an even playing field. When Eve tells Morgan to stop the backlash, Morgan says that she can't, as she isn't the one who created it. Eve must choose between stopping Morgan and saving the kids, and she chooses to save everyone.

The team finishes preparing the Farraday cage, but need everyone inside it to protect them. Amy gets on the stage and announces that she's created a Tesla coil, but that everyone who isn't in the centre of the room will be electrocuted, relying on her reputation as the best to get them to listen. With everyone gathered, Eve, Jacob, Ezekiel, Cassandra, and Amy each position themselves to form one point of the pentagram, and get the Farraday cage working as the magical backlash hits the school.

In the middle of the backlash, time stops around Eve, and she finds Morgan recharging her power. Eve attempts to pick up their fight again, but Morgan dismisses her, and laughs when Eve asks if she's going to use magic to rule the world. Morgan reveals that her plan is to hide, saying that the world is doomed, and that Eve has already been woven into the Loom of Fate. She also has a message for Jenkins, which she passes along to Eve in Latin before vanishing and returning Eve to the normal flow of time.

The Chicagoland STEM Fair wraps up with the superintendent taking over, informing everyone that Amy has been disqualified for disregarding the safety of the attendees, and that Lucinda McCabe was taken to the hospital with injuries. He then announces the winner: Leonard Cole, who had built the baking soda volcano. While Leonard very excitedly makes his way to the stage, Amy and Dashell share a moment in the crowd. Afterwards, Ezekiel congratulates Cassandra on the pentagram, calling it the best project of the day, and gives her the Chicagoland STEM Fair trophy--stolen, of course--for first place in the category of "Mathemagics".

Back in the Annex, Eve is startled by an angry, dishevelled Jenkins, who berates her for letting Morgan Le Fay get away. When she asks him how he knows Morgan, he says that they've both lived a long time, but Eve doesn't believe him, pointing out that you don't hate strangers that much. She gives Jenkins the message she received from Morgan for him, and he translates it as, "Do not fear the villain... Fear the hero." Jenkins tells her that an end is coming, and she needs to learn to win the war, not the battles, or that none of them will survive.


Main Cast[]

Guest Cast[]


  • Fittingly during this episode, Cassandra is seen wearing a necklace with a Serotonin Molecule on it in reference to her STEM background. Serotonin is thought to be related to happiness and well-being in mammals.
  • A small figure of Nessie is seen in Jonah Gordon's room.
  • This episode was filmed fifth[3] and was intended to air ninth--just before the finale.[4] It was meant to be a team-centric episode, with a good deal of Jenkins as well. In intended airing order, it would have followed "And the Heart of Darkness", and continued building on the revelations about Cassandra's background and personality from that episode.
  • The episode was built around a number of aspects: the concept of what magic might look like in the modern world[5]; how witchcraft worked in this setting, and which group of people would be the least likely coven[6]; and high school, a place with "one of the most screwed up social structures on earth", with all the related identity issues and competition that comes with it[6].
  • Using a high school as a setting allowed the writers to build more of the characters by exploring who they were in high school and how they felt about it, and also let the production shoot mainly in one location (a "bottle episode")[3].
  • The science fair projects were almost entirely loaned to the production team by local students[6].
  • The project about how otters are history's greatest monsters, however, was created in reference to "a running argument in the Writers Room" about how otters are the monsters of the sea[6], which was originally brought up by one of the writers assistants on the show[3].
  • John Rogers describes this as a very X-Files style of episode[3], but also that they wanted to deconstruct the '90s goth kids doing magic cliché, which is why they went with the alpha kids as the magic-users instead[6].
  • Both Bex Taylor-Klaus (Amy Meyer) and Alicia Witt (Lucinda McCabe/Morgan Le Fay) were so well-liked by everyone that they'd hoped to bring both characters back later, but couldn't work out the scheduling. Morgan was meant to come back in season 2's "... And the Happily Ever Afters", but Alicia had been booked on another show the same day that she was asked to come back[3].
  • The scenes where Eve and Stone try to interrogate Leonard were not originally meant to be on a stage set, but when they found the stage during planning, they decided to build the set and use it for the scene[3].
  • "Lucinda" being able to walk through the back door and into the Annex was a sign to viewers that she wasn't who she seemed[3], and that she was "hella-magic"[6].
  • Along with Dulaque being called "Son of Ban" in "And the Apple of Discord", the reference to Jenkins as "Galeas" in this episode is one of the major clues to their actual identities.
  • John Rogers wrote the scene between Jacob Stone and Dashell, including the use of Byron[6].
  • There was originally a sub-plot planned for this episode where everyone got entirely too involved in the social lives and high school politics of the kids, but it was cut[3].
  • They also planned some other bad things that could happen to the victims of the spell, including "sweating blood" and "all their bones turned to putty, they're basically a flesh sack"[3].


  • Eve Baird: "I'm just saying, what kind of magical, world-ending apocalypse could possibly happen at a cheesy high school science fair?"
  • Ezekiel Jones: "High school's like prison. You find a crew to run with and keep all the other crews down."
  • Jenkins: "I was just going to stand around all day, waiting for you to call, and then I remembered I have free will."
  • Jacob Stone: "You see, so the... the jocks and the, uh, geeks and the goths... Those are all roles we play. Those are costumes we wear."
    Dashell: "I bet nobody ever beat you up for saying poetry."
    Jacob Stone: "No, they didn't, not for that, not for reciting poetry. You know why? 'Cause I wore my damn costume. I wore it like a second skin. And I wore it for too long."
  • Jenkins: "Are you familiar with the quote, 'Any sufficiently advanced technology is indistinguishable from magic'? It turns out, any sufficiently disguised magic is indistinguishable from technology."
  • Cassandra Cillian, re: her parents: "I think the dream that they had in their head was too big for me to carry. I think they loved it more."
  • Morgan Le Fay: "I never hurt anyone, darling. That's the scam. Put magic in the hands of mortals, and they will inevitably destroy each other."
  • Jacob Stone: "I was a surveyor for ten years. I can estimate distance like a tachymeter."
  • Elysse: "The sea otter is generally considered adorable, but it is, in fact, history's greatest monster, and if we don't take action immediately, it will take over the planet and destroy us all."
  • Morgan Le Fay: "Guardian, on your best day, you might be able to muss up my hair, and you already had your best day."
  • Eve Baird: "I am a Guardian. I am not a hired gun. I am not here just to kill."


External links[]


  1. Watch Episodes of The Librarians on TNT Drama - TNT
  2. 2.0 2.1 Listings - LIBRARIANS, THE on TNT - The Futon Critic
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Rogers, John, Marc Roskin, and Rebecca Romijn. Audio Commentary. "And the Rule of Three", The Librarians, season 1, episode 7, TNT, 2016.
  4. Rogers, John. "LIBRARIANS #106 "Fables of Doom" answer post" Kung Fu Monkey, 10 Jan. 2015,
  5. Rogers, John and Kate Rorick. "Writer Vlog: And the Rule of Three." The Librarians, TNT, 2016.
  6. 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Rogers, John. "LIBRARIANS #107 "Rule of Three" answer post" Kung Fu Monkey, 26 Jan. 2015,