Jonas and The Giver plan for him to escape during the next Ceremony of Twelve.
When Jonas sees his father kill a newborn baby, he no longer desires to go back home. He realizes that his community is not the peaceful and gentle place he thought it was. He is shocked and horrified. At this point, Jonas and The Giver begin to formulate a plan. Jonas will escape, returning the memories to the community.
When Jonas asks what would happen to him if he were to have an accident and die, The Giver begins to see that there is a possibility to return the memories to the community and get rid of Sameness and the atrocities that come with it.
If you floated off in the river, I suppose I could help the whole community the way I've helped you. It's an interesting concept. I need to think about it some more. Maybe we'll talk about it again sometime. But not now. (ch 19, p. 145)
This is the beginning of the plan. Jonas is going to sneak out during the ceremony when everyone is distracted. By the time they notice he is gone, he will be far away. The people will be confused, but The Giver will help them deal with it.
Unfortunately, the plan does not work. When Jonas realizes that Gabe is about to be released, he has to take him and run in the middle of the night. He knows that he has broken three rules, and if he is caught they will both be released.
He thought of the rules he had broken so far: enough that if he were caught, now, he would be condemned. (ch 21, p. 165)
Instead of following the plan, Jonas steals food and his father’s bicycle. He and Gabe travel as far as they can into Elsewhere, all the time evading search planes.
Jonas and The Giver’s plan demonstrates a need to return the community to normalcy, the way it was before Sameness. They both realize that killing people for breaking three rules and murdering babies because they do not sleep through the night is horrible. Jonas is the only one who can same the people, because he has been Receiver long enough to have a significant amount of memories, and plenty of memories of pain. The people do not know what they are in for, and the reader never does find out what happens to them.
The ending of the book is ambiguous, meaning that it is not perfectly clear. Jonas finds a sled, which might be real or a memory. He hears music, but that might be real or not. He might be in Esewhere, but what is Elsewhere? The reader does not know whether he has died and gone to Heaven or been rescued.
Lowry, Lois (1993-04-26). The Giver (Newbery Medal Book). Houghton Mifflin Harcourt. Kindle Edition.