01PLOT

April has called the Turtles to her apartment. She explains that while trying to bathe Mayhem, he teleported himself into her mirror, and he can't come back out. Raphael offers to help, but ends up smashing everything except the mirror. Donatello questions this, and Raph realizes he should smash the mirror. Leonardo advises against this, as this might trap Mayhem permanently. Michelangelo notices that Mayhem is starting to fade away, and begs Donnie for a solution. Donnie suggests they visit a library (but needs to explain to his brothers what libraries are).

They sneak into a regular library, and Donnie uses his mystic-detecting goggles to find something useful. He spots mystic energy coming from a book, and when he opens it, the book swallows the Turtles, sending them to a massive Mystic Library full of Yōkai employees and patrons. Donnie is overjoyed to be there, and goes to talk to the librarian, a large bat yōkai. Donnie quietly explains what is going on while the other Turtles mess around behind him. The librarian tries directing them to the kiddie room, but Donnie tells her about his library-related accomplishments. She allows the Turtles to search for material that will help Mayhem, but they must be quiet. She points to her Hush-Bats; smaller bats with sensitive hearing. If anyone speaks louder than a whisper, the Hush-Bats will lock them up in the kiddie room. Mikey immediately tests this by shouting. The Hush-Bats take him away, and bring him to the kiddie room, where an army of yōkai kids accost their "new toy."

Raph, Donnie, and Leo find the library's catalog; a crystal ball. Donnie uses it and finds a book on escape rituals, as well as where in the building it is located. Raph asks Donnie to write down the directions, but Donnie has memorized it in song form. As the Turtles begin their trek, they are spotted by Foot Brute and Foot Lieutenant. Brute suggests that since the Turtles are always ruining their plans, they should ruin whatever the Turtles are up to.

Donnie starts rapping the directions to the section the book is located, but in his excitement, gets too loud. The Hush-Bats take Donnie away to the kiddie room, where he discovers that Mikey has been fully accepted among the yōkai kids. Mikey promptly declares Donnie a 'new toy'.

Raph and Leo press onward, struggling to remember the rhyme, but they run into the Foot Clan. Both groups quickly realize that they can't fight each other, so they resort to trying to make the other group laugh. Leo trips over a book, which makes Brute laugh. He gets carried away by the bats. Lieutenant retaliates with miniature origami ninjas that tickle Leo. Leo laughs and gets taken by the bats, but calls to Raph that he sees the hall that the book is in. Lieutenant sends more tiny ninjas to tickle Raph, but Raph blows them onto Lieutenant. Lieutenant laughs at the tickling and is taken away.

Raph's smartphone starts to ring, and before he can explain to April that he has to be quiet, April shouts that Mayhem has nearly faded away completely. This alerts the bats, and Raph runs to the hall. He recalls Donnie's rap bit by bit, while being chased by the horde of bats. He gets to a section where bookcases are flying around, and uses his mystic Tonfā to create a giant version of himself to combat the obstacles and smash through walls. After going up a waterfall, he enters the correct room and sees the book on escape rituals. The bats start to surround him, but he uses his giant self to throw his real self at the bookcase. The collision sends Raph and the bats out through the wall, and into the view of the librarian. Raph catches the book, and the bats swiftly take him away to the kiddie room. Raph tries to gather his brothers and leave, but the librarian bursts in, saying she will pummel Raph into papyrus for destroying her library. But, before either of them can do anything, Mikey, who has been made Chief of the kiddie room, declares the librarian as a "new toy." The yōkai kids descend on the horrified librarian.

Back at April's bathroom, the Turtles complete the spell to free Mayhem. Mayhem pops out of the mirror and scratches Raph's face in thanks. April hugs Mayhem, but is repulsed by his smell. She tells him that he needs to bathe now, and Mayhem teleports back into the mirror. Raph opts to smash the mirror this time.

02CAST & APPEARANCES

Bat LibrarianDEBUT

Gillian Vigman

Donatello

Josh Brener

Hush-BatsDEBUT

Leonardo

Ben Schwartz

Raphael

Omar Benson Miller

ALSO APPEARING

April O'Neil · Kat GrahamFoot ClanFoot Brute · Maurice LaMarcheFoot Lieutenant · Rob PaulsenMiniature Origami NinjaMayhemMichelangelo · Brandon Mychal SmithYōkai Kids · Maurice LaMarche and Rob Paulsen

03OBJECTS, VEHICLES & PLACES

OBJECTS & VEHICLESBig Mama's trainBooksChiroptera MorsComplete Compendium of Escape RitualsDon't Take Me for GraniteHow to Avoid Tripping & Other Balance TipsPeriodicallyCrystal ball library catalogTonfā

LOCATIONSNew York CityO'Neil apartmentNew York Public LibraryMystic Library

SPECIESHumanAltered humanMutant turtlesOrigami NinjaYōkai

04SCREEN GRABS

4 frames. Auto-matched screencaps via Fancaps.net.

05MEMORABLE QUOTES

Donnie: But Raphael, a library is a treasure hunt. You never know what gems you may find along the way!

Donnie: What? Would a child have a platinum library card? Would a child have won the national library competition 3 years in a row? Would a child be an expert on Dewey decimal mathematics? I can divide by biographies!

Mikey: \sharp inhale\ Echo! I regret nothing!

06TRIVIA

A Pac-Man easter egg appears very briefly in an artwork on the wall in the O'Neil apartment. The artwork is arranged to resemble Pac-Man eating pellets, but Pac-Man has green skin and an orange bandana (like Mikey) and the pellets are slices of pizza.
A few Easter eggs relating to the Mad Dogs' Renaissance-era namesakes are briefly seen when Donnie explains the "sum knowledge of entire civilizations".
The Mona Lisa, a painting created by Leonardo da Vinci is seen with a blue bandana and holding a Katana.
Italian Renaissance painter Raffaello Sanzio da Urbino, also known as Raphael, is seen wearing a red mask.
Michelangelo's statue of David can be seen wearing a pair of orange shorts.
The phrase "New toy!" said by a Yōkai child, then Mikey, is a reference to Disney/Pixar's _Toy Story 3_ when a Jack-in-the-box says the same phrase whenever a new toy arrives at Sunnyside Daycare.
Donnie's Mystic Library rap was written to match the rhythm of the rap track from the 2012 TV series theme song.[[1]](#cite_note-1)[[2]](#cite_note-2)
It was revealed in August 2019 in a Tweet[[3]](#cite_note-3) that the official lyrics for Donnie's Mystic Library rap are:
Down the stairs past the ibis tapestry
Sliding bookcase after bookcase shows the way to the hall
Up the pole through a hole to the waterfall
Donatello, with a book in his hand
Saves the day and proves to everyone that he is the man!
Po-po comes in and takes him away!
But Donnie-D will live to fight another day!
It was revealed in July 2022 by _Rise of the TMNT_ staff writer Ron Corcillo in a Tweet that, "The Ibis bird on the tapestry that appears in this sequence is reference to the Harvard Lampoon. The Ibis is one of the Lampoon's symbols, planted by a Lampoon alumnus who shall remain nameless."[[4]](#cite_note-4)
The train from "Insane in the Mama Train" makes an appearance as a toy in the kiddie room.
Raph swallowed his smartphone when April called him for the last time in the library.
In August 2022, _Rise of the TMNT_ staff writer Russ Carney stated in a Tweet concerning Donnie's unconventional use of the word "loom" in his Mystic Library rap that, "To be fair, I have no idea what a 'loom' is supposed to be in this context, but we thought it sounded cool. Yes, a weaving loom is the device that you use to weave fabrics. However, in the context of a mystic library, the word doesn't exactly make sense, but it sounds cool."[[5]](#cite_note-5)[[6]](#cite_note-6)
In August 2022, Carney stated in a Tweet, "OK, my new made-up idea for why it's 'Loom 16': The mystic library contains all information terrestrial and supernatural. The books are stored in metaphorical 'looms' where knowledge can be woven together. You buying it? Don't forget the ibis tapestry! #rottmnt"[[7]](#cite_note-7)
In October 2022, Corcillo stated in a Tweet, "Dude, relax. We made up a weird meaning of a word because it's a yokai place and sometimes the yokai speak differently from the way we do. So we imagine they use 'loom' to mean an intersection because a loom weaves things together at right angles. It's meant to be kooky!"[[8]](#cite_note-8) With Carney also stating in a Tweet, "And the mystic ibis tapestry had to be woven somehow."[[9]](#cite_note-9)
In September 2023, Carney stated in a Tweet, "Honestly, 'loom' is a cool word. In the context of a mystic library, 'loom' could suggest that the magic of the underground is somehow woven into the reality of the topside, and these library areas are maybe how you work that magic. Remember the Ibis tapestry? . . . ."[[10]](#cite_note-10)
On a dresser outside of April's bathroom is a maneki neko figurine that wears a kimono.
The objects that Mikey grabs out of Donnie's Spider Shell are: a solved Rubik's Cube, a pink wrist watch, a beaker, a purple flashlight, a ruler, a pink pencil, a baster, a pink eraser, a vial of green liquid, a triangle ruler, a pink pen, a USB flash drive, a vial of pink liquid, a yellow pencil, a microscope, and a grey tabby cat.