03E15 - The Boiling Rock

Mai, Ty Lee and Azula show up in this episode. Mai - who is in love with Zuko - is the warden's niece. The Warden tortures the prisoners who were captured during their escape attempt, and learns that one of his guards is a fake. The prisoner who gave the information does not betray Sokka. Zuko confronts Mai and tells her that he is "trying to save the Fire Nation" - she replies that he's a traitor. Sokka and his father think up a plan to escape from the island via the cable car - using the Warden as a hostage. While the tortured prisoner creates a diversion by starting a riot in the prison yard, Sokka, Zuko, Haruto and Suki kidnap the Warden and make their way to the cable car. While the cable car is in motion, Azula and Ty Lee attempt to stop it. A battle ensues. When the guards on the island - ordered by a shout from the Warden - jam the cable car works and attempt to cut the cable so the gondola will fall into the boiling lake, Azula and Ty Lee flee the gondola - but Mai intervenes to save the escapees. She assails the guards jamming the cable car works, saying "I'm saving the one I love", and escape is a success. The escapees are still trapped on the volcano, but find Azula's war balloon. They use it to return to Aang and the other young warriors who are hole up in the Northern Air Temple.