- This article is about the episode. For the place, see Wan Shi Tong's Library.
At a desert oasis, the group encounters a professor who tells them of a hidden library overseen by a spirit in the desert. Inside, Sokka discovers a crucial weakness of the Fire Nation's that has the potential to end the War: the date of an upcoming solar eclipse, which will cripple the firebenders' abilities. The spirit of the library, Wan Shi Tong, refuses to allow them to leave with the knowledge, and sinks the library into the sand. The team narrowly escapes the library but is devastated by the loss of Appa, who is captured by sandbenders in their absence.
The scene opens with Aang sitting on the ground, looking over a vast savanna landscape. The gang stands behind the seated Aang, who is holding a flute in his hand; Sokka asks: "What's out here?" As Toph bends down to touch the ground, she responds, "A lot actually." Just as she is about to elaborate, Aang interrupts her, telling her not to ruin the surprise. He plays a musical note on the flute and a groundhog-like creature emerges and repeats the same note. After Aang plays several more notes, Sokka plugs his finger into the end of the flute in frustration and states that they need to make plans. Toph points out that they are making plans – mini-vacation plans. Sokka argues they do not have time for vacations. Aang points out that he is diligently working his "arrow off" with Toph and Katara to master the elements and Katara agrees there's nothing wrong with enjoying themselves during their downtime. Sokka expresses concern at lacking inside information about the Fire Nation and the fact that even if Aang masters the elements, they would be unable to locate the Fire Lord, let alone defeat him. Sokka states they need intelligence in order to win the war. Katara aptly states, "All right, we'll finish our vacations and then we'll look for Sokka's 'intelligence'."
For her mini-vacation, Katara chooses the Misty Palms Oasis. However, the gang soon finds that the Misty Palms Oasis' reputation has gone downhill in the past one hundred years. They go into a bar-like establishment where an employee prepares a mango. The customer being served accidentally bumps into Aang, spilling some of his drink onto him. Aang uses his airbending to dry himself. The customer, excited to meet an airbender, introduces himself as Professor Zei of Ba Sing Se University. He begins quizzing Aang as though the latter is a science specimen. Sokka inquires as to whether the professor has a more recent map, and the professor unrolls a map showing a vast desert with routes marked where he has gone in search of a Knowledge Spirit's library. With the possibility that the library may have information to be used against the Fire Nation, Sokka dramatically announces his choice of location for the next mini-vacation to be the library. The professor states it is impossible to cross the desert on foot, but the gang introduces him to Appa. Sandbenders, earthbenders who specialize in bending sand, are attempting to steal Appa as the team walks out of the cantina, but the professor shoos them away.
The group heads out in search of the enormous library. After a long search, Sokka finally spots a tower-like structure sticking out of the sand. They investigate, but conclude that the tower is not what they are looking for, as it is much smaller than the library's illustration. Just as they are about to give up and go back, a fox carrying a scroll races up the side of the tower and enters via a window at the top; Sokka realizes this is the library, and that most of it is just underground. Devastated that his lifelong dream of finding the Knowledge Spirit's library is nearly buried, the professor drops to the ground and begins to excavate. Toph places her hand on the tower and announces the library is intact under the sand. Everyone enters the library via the open window, save for Appa, who does not fit through the opening, and Toph, who declines due to not being able to read.
After entering the library, they hear something approaching and hide behind ornate columns. A huge black, white-faced owl walks forward. After observing his surroundings for a few moments, the owl speaks, telling the group he is aware of their presence. Professor Zei comes out excitedly and introduces himself. The owl is less than impressed and tells the professor he should leave or he will stuff him like an animal trophy. The others come out from hiding, and Sokka asks if he is the spirit who brought the library to the physical world, to which the owl confirms this. The Knowledge Spirit, named Wan Shi Tong, informs them that humans are not permitted in the library anymore because they abuse the knowledge, using it only to gain leverage on other humans. After Aang promises they will not abuse the library's knowledge, the owl relents but only after each provides some knowledge for his collection. The professor offers a first edition book; Katara offers a waterbending scroll; Aang offers his wanted poster; and Sokka offers a specially-tied knot. After accepting these donations, though less than impressed with the knot, the Knowledge Spirit descends into the lower levels of the library, allowing the group to look around.
Meanwhile, Toph attempts to make small talk with Appa outside. She explains to Appa that her seismic sense is majorly impaired because of the looseness of the sand, making her vision "fuzzy".
Back inside the library, the group looks around where it is learned that in a previous life, Aang was once left-handed. Sokka finds a parchment stating the darkest day of the Fire Nation marked with a date. The group seeks out a Fire Nation wing of the library, only to discover that everything has been destroyed by firebenders, much to their shock. A fox suddenly appears and indicates that it will lead them to another source of information. The fox opens the door to a planetarium and shows them how to use a mechanism to operate it. Katara suggests entering the date from the parchment and running the machine. Once this is done, they realize a solar eclipse will incapacitate the firebenders in a manner similar to how the removal of the moon affected the waterbenders. Just as Sokka is gloating about the defeat of the firebenders, the Knowledge Spirit appears. Understandably angry, he flaps his wings and begins sinking the library. The group starts to flee with the owl chasing them.
Outside, Toph realizes the library is sinking. Her initial attempt to prevent this proves fruitless, as she begins to sink into the sand herself. However, she manages to twist some sand around her feet into sandstone and uses her fists to slow the library's descent.
With Wan Shi Tong still in hot pursuit of the team, Sokka persuades Aang to return to the planetarium to discover if or when the next solar eclipse will happen before the return of Sozin's Comet. The spirit continues to chase Katara and the professor as Aang and Sokka head back.
While Toph continues to hold up the library, sandbenders arrive on scene, intent on capturing Appa. The earthbender, preoccupied with preventing the library from sinking and unable to use her seismic sense effectively, is unable to determine their exact identity or location.
Aang and Sokka begin checking dates from that day to the arrival of Sozin's Comet, and eventually find the date of the next solar eclipse, which is a few months away.
Toph is alternating between holding up the library and firing misaimed blasts at the sandbenders, but soon realizes she must choose between protecting Appa or preventing her friends' deaths. She plants her fists in the library again and, pained at hearing Appa's calls of distress as he is pulled away, sadly apologizes for being unable to help him.
The Knowledge Spirit catches up to Katara and warns her that he is versed in all types of waterbending styles, thus rendering any attacks she may use worthless. She is saved when Sokka drops down on the owl, knocking him unconscious and saying, "That's called 'Sokka Style'. Learn it!" As they begin to ascend the rope through which they entered, Sokka calls to the professor, who refuses to leave. The spirit regains consciousness and shakes Sokka and Katara off the rope, but Aang manages to catch them and flies them out of the library. Realizing they have escaped, Toph releases her grip on the library, and it vanishes into the sand. Although initially happy at the discovery of the Fire Nation's weakness, the mood changes once they realize Appa is gone. A tear runs down Aang's face.
- Written by:
- Directed by:
- Additional voices:
- Dee Bradley Baker
- Raphael Sbarge
- Main article: Transcript:The Library
- Main article: Writing in the World of Avatar
- Main article: Avatar Extras for Book Two: Earth
- When Sokka discusses invading the Fire Nation, he sarcastically says, "Should we just head west until we reach the Fire Lord's house? Knock, knock. Hello, Fire Lord? Anybody home?" Ironically, during the eclipse, Aang travels to the Fire Lord's palace and asks if anybody is home.
- Sokka's dramatic declaration of his desired mini-vacation destination mirrors Katara's dramatic declaration of earthbending use in "Imprisoned" both in animation style and pose.
- Professor Zei asks Aang what his people's primary agricultural product was, to which Aang wonders if fruit pies are an agricultural product. This is a reference to a flashback in "The Southern Air Temple" in which Aang and Monk Gyatso practice airbending using fruit pies.
- As revealed in "The Siege of the North, Part 2", Zhao visited an "underground library". Here, Wan Shi Tong mentions him as a firebender who came a few years back.
- The wanted poster that Aang gives to Wan Shi Tong is believed to be the same wanted poster he took off the message board in "The Deserter".
- The waterbending scroll Katara gives to Wan Shi Tong is the same one she stole from the pirates in the episode "The Waterbending Scroll".
- During this episode, Aang comes across a book which depicts the meeting of a human and a lion turtle, foreshadowing his own encounter with one during the series finale.
- When Katara tries to use waterbending against Wan Shi Tong, he states he has studied all types of waterbending, including Foggy Swamp Style. This is the style used by the Foggy Swamp Tribe as seen in "The Swamp".
- The scrolls Sokka steals from the library help Katara navigate in "The Desert" and are referenced in "The Serpent's Pass".
- This is the first time Admiral Zhao has been seen or mentioned since his death during the Siege of the North.
- When Aang is playing the flute, his fingers move despite playing only one pitch. When flutists uncover and cover holes with their fingers across the instrument, the velocity of the air changes, thus creating different pitches. This is not proper for only holding a single pitch.
- Also, when Sokka plugs the front hole of the flute, it stops playing a specific pitch, whereas in an actual flute, the front hole is not the point from which the sound is emitted, and therefore, plugging it will not stop the flute from functioning.
- In several scenes in the Misty Palms Oasis bar, Sokka and Katara's belts are blue instead of white.
- Sokka is the first to enter the library through the window. However, he is the second to last person to climb down the rope when they reach the floor of the library.
- As Katara, Aang, Sokka, and Professor Zei are climbing down the rope into the library, Momo is missing in a few frames.
- When Aang and the others enter the library, the bridges are "+" shaped, offering four paths of access. Yet near the end of the episode, when Wan Shi Tong is chasing the group, the bridges only go one way across.
- After Katara tells Aang that he was left-handed in a past life, when Sokka reaches for a scroll on the bookshelf, his boomerang is missing. In the next frame, it is back.
- The scroll that shows the darkest day in Fire Nation history is evidently burnt and ripped around all the edges, but after Sokka takes it and rolls it up, it has the appearance of an intact scroll.
- When Sokka decides to return to the planetarium to discover the date of the next eclipse, Momo's fur becomes black.
- When Wan Shi Tong sinks the library, sand begins pouring into the planetarium. However, when Sokka and Aang return, the sand is no longer flowing and no piles of sand can be seen.
- Along with the following episode, "The Desert", this episode aired as the one-hour special, Avatar: The Fury of Aang.
- The library looks like a mix of Turkey's Hagia Sophia and India's Taj Mahal.
- Wan Shi Tong represents himself as a barn owl. This is a reference to the symbol for Athena, the Greek Goddess of Wisdom, whose symbolic animal is an owl.
- The pictures on the dial are the Chinese zodiac, which is for choosing the year.
- Although an owl is a traditional symbol of wisdom and viewed as an animal that may harbor mysteries or secrets, the owl is, in actuality, not a very intelligent bird.