Jonas and The Giver's plan hits a snag that night: at dinner, Jonas's father tells the family that the previous night he brought Gabriel to a Nurturing Center to see how he would sleep, and that Gabriel was unable to sleep at all. As a result, the staff of the Nurturing Center, including Jonas's father, unanimously voted that Gabriel should be released on the following day.
Now that Jonas (and the reader) knows what release is, Jonas's father calmness about killing a baby who has lived with him for a year seems monstrous. That this caring man would think nothing of such an action justifies Jonas's desire to enlighten and transform the community.
Jonas refuses to let Gabriel be killed. When everyone is asleep, he takes some leftover food and steals his father's bicycle (which has a child seat for Gabriel). Terrified, with only his own courage to support him rather than all the memories of courage he had expected to have from The Giver, he rides across the river and out of the community.
This is the first choice Jonas makes without The Giver's guidance. He decides that an individual life is more important than the community, and makes his escape not on the borrowed courage of a memory but with his own courage.
Jonas rides all night, then hides with Gabriel during the day as planes fly overhead searching for them. To make Gabriel sleep, Jonas transmits memories of exhaustion to him. To evade the plane's heat-seeking tracking devices, he transmits memories of snow to keep their bodies cold. After several days of traveling at night and hiding and sleeping during the daylight hours, the planes cease to appear.
The novel comes full circle here. Jonas experiences his first real fear since seeing the planes in the beginning of the novel. Yet now, rather than following the instructions given to him over a loudspeaker, he uses his own judgment. Unlike the other members of his former community, he is a true adult.