Simplify the following text for a Grade 7 native English-speaking person.
Original: But Zuko survives the attempt on his life and , with Iroh 's help , sneaks aboard Zhao 's lead ship as his fleet departs for the Northern Water Tribe to execute the plan he and Ozai set up with the scrolls from the Library detailing the spirits there .
Simplified: Zuko survives the attempt on his life with Iroh 's help . He sneaks aboard Zhao 's lead ship as his fleet departs for the Northern Water Tribe to capture the Avatar .