Book One: Water
2005 · 20 episodes · 8h 17m in all · 8.0/10
Katara and Sokka (a brother and sister from the Southern Water Tribe) discover the Avatar (a 12-year-old Airbender boy named Aang) frozen in an iceberg. Together the three begin their journey to the North Pole to find a master waterbender so Aang can begin his Avatar training!

Episodes

1. The Boy in the Iceberg
21 Feb 2005 · 24 min · 7.9/10
Two teenage siblings (Sokka and Katara) living in the South Pole discover a very strange boy (Aang), along with his pet flying bison Appa, in an iceberg. But can they trust him when he accidentally draws the war to their village's doorstep?

2. The Avatar Returns
21 Feb 2005 · 24 min · 7.9/10
Katara and Sokka discover that Aang is the long-lost Avatar and must rescue him when a firebending prince named Zuko kidnaps him.

3. The Southern Air Temple
25 Feb 2005 · 25 min · 8.1/10
Aang is excited about going home for the first time in one hundred years, but he is shocked to find out that the temple is deserted. Aang tells Sokka and Katara about his childhood as they explore the temple, but they soon discover something that Aang never expected. Meanwhile, Zuko must make repairs to his ship and the only way he can do it is to dock his ship at his rival's naval base.

4. The Warriors of Kyoshi
4 Mar 2005 · 24 min · 7.8/10
The gang arrives at Kyoshi Island and are captured by some Kyoshi warriors. When Aang reveals that he is the avatar, news quickly spreads out, eventually reaching Zuko, who then goes to Kyoshi Island to capture him.

5. The King of Omashu
18 Mar 2005 · 25 min · 7.9/10
Aang's abilities as an airbender are challenged by a strange king.

6. Imprisoned
25 Mar 2005 · 25 min · 7.8/10
In a nearby Earth Village, the gang meets a teenage earthbender named Haru. This village lives in fear of the Fire Nation, for soldiers there capture any earthbenders they can find. After Haru is captured for earthbending, Katara is compelled to rescue him.

7. The Spirit World: Winter Solstice (1)
8 Apr 2005 · 25 min · 8.0/10
Aang and friends visit a village being terrorized by an angry spirit. Iroh is captured by Earth Kingdom soldiers.

8. Avatar Roku: Winter Solstice (2)
15 Apr 2005 · 24 min · 8.6/10
To contact the spirit of the previous Avatar, Aang must reach a temple in the Fire Nation before the sun sets on the following day. There he will learn what he must do to restore balance to the world. Zuko must defy his banishment to follow Aang.

9. The Waterbending Scroll
29 Apr 2005 · 25 min · 7.7/10
After Katara attempts to teach Aang waterbending, but realizes that he is learning it much faster than she is, she is desperate to improve her abilities. When Katara inadvertently stumbles across a waterbending scroll that can help improve her abilities at a pirate’s store, she decides to steal it, realizing that she couldn’t hope to afford it.

10. Jet
6 May 2005 · 25 min · 7.6/10
While traveling towards the North Pole, the group almost gets captured by the Fire Nation. However, when a charismatic young man and his band of rebels attack the Fire Nation camp and rescue them, they learn that they are trying to resist the Fire Nation’s motives to expand their territory. Katara and Aang really enjoy their time with the band of rebels, but Sokka soon discovers that they aren’t as noble as meets the eye.

11. The Great Divide
20 May 2005 · 25 min · 7.1/10
While on their way to the North Pole, Aang and his friends arrive at a giant canyon where two groups of refugees are bickering over who should get to go across. Aang decides to walk across with the two groups to ensure they don’t fight one another. However, he soon learns that the two tribes have been feuding for one hundred years and they both believe their actions are justified. But when the predators inside the canyon start to come out, Aang is stuck trying to defend both tribes from each other and the vicious wildlife.

12. The Storm
3 Jun 2005 · 25 min · 8.6/10
Sokka accepts a job for a fisherman who is looking for someone to help him out with his fishing. After the fisherman finds out Aang is the Avatar, Aang runs away in response to the fisherman's hostile reaction. When Katara finds Aang, he begins to reveal his life before he was frozen in the iceberg. Meanwhile, after Zuko gets into a fight with his crew, Iroh tells them about Zuko's complicated past, attempting to make both sides understand each other.

13. The Blue Spirit
17 Jun 2005 · 25 min · 8.7/10
While Aang, Katara and Sokka are traveling, Sokka gets a fever. Katara and Aang try to help Sokka, when Katara also catches the fever. It's up to Aang to go up on his own to save his two friends. But before he can get the medicine he is captured by the newly promoted Admiral Zhao and put in Zhao's fortress.

14. The Fortuneteller
23 Sept 2005 · 25 min · 7.7/10
When the group tries to help a man who is being attacked by a platypus-bear, they discover that the local town has a fortuneteller named Aunt Wu in it, who has been forecasting the town's fate for years. But when Sokka and Aang discover one of the fortuneteller's most vital predictions is dead wrong, they have to develop a plan to convince the stubborn townspeople that their beloved Aunt Wu was wrong.

15. Bato of the Water Tribe
7 Oct 2005 · 25 min · 7.6/10
Aang feels neglected as Katara and Sokka reunite with Bato, an old friend of their father’s from the South Pole. They begin to reminisce on their times in the past while they wait for a message to arrive from their father. Aang believes Katara and Sokka will abandon him and go out to find their father should the message arrive. However, when the messenger gives Aang the message to give to Bato, Aang betrays his friends in a way Katara or Sokka could never imagine. However, when Zuko recruits a bounty hunter named June to track Aang down, his friendship is put to the test as he must deal with the fact that he betrayed his friends while defending himself from yet another fight.

16. The Deserter
21 Oct 2005 · 25 min · 8.4/10
Team Avatar learns of a firebending master who deserted the Fire Lord’s army. This may be Aang’s only chance to learn firebending, but the deserter warns that the young Avatar is not yet ready for the control a firebender needs.

17. The Northern Air Temple
4 Nov 2005 · 25 min · 7.7/10
Arriving at the Northern Air Temple, Aang is upset to discover the sacred place being desecrated by a brilliant inventor intent on renovating it into a home for his displaced family.

18. The Waterbending Master
18 Nov 2005 · 25 min · 8.3/10
When Aang tries to find the north pole, he is found by the north pole instead. As they are taken there, Aang and Katara are eager to find a waterbending master, only to discover that girls are not allowed to learn waterbending.

19. The Siege of the North (1)
2 Dec 2005 · 25 min · 8.6/10
Zhao begins to launch his attack against the Northern Water Tribe. As the walls of the prestiged city begin to fall, the Avatar taps into the spirit world and seeks the help of one of the oldest spirits, in hopes of saving one of the most prominent areas of the world.

20. The Siege of the North (2)
2 Dec 2005 · 26 min · 8.9/10
Aang returns from the spirit world to a big surprise. Meanwhile, Zhao and his forces continue to press deeper into the Northern Water Tribe. Iroh makes a powerful stand and Zuko struggles to keep his plan intact.
Avatar: The Last Airbender Book One: Water: quick answers
How many episodes are in Avatar: The Last Airbender Book One: Water?
Book One: Water of Avatar: The Last Airbender has 20 episodes, about 8 hours in total.
When did Avatar: The Last Airbender Book One: Water come out?
Book One: Water premiered on 21 Feb 2005.
What is the best episode of Avatar: The Last Airbender Book One: Water?
By viewer score, episode 20, “The Siege of the North (2)”, at 8.9/10.