Phoebe and Jane represent innocence. Jane is a catalyst that sets the plot in motion. She is a friend of Holden's. When he finds out she has a blind date with his handsome roommate Stradlater, who epitomizes a dangerous phoniness to Holden (Holden calls him "unscrupulous"), he fears Stradlater will take advantage of Jane. When Stradlater returns from the date, Holden's fear and jealousy overwhelm him, and he gets into a fistfight with Stradlater. After this, Holden flees. He says:

I sort of needed a little vacation. My nerves were shot. They really were. 

He packs a suitcase, sells his typewriter, and leaves Pencey. He is flush with a "wad" of money from his grandmother.

If Holden wanted to protect Jane, he also longs to protect his younger sister, Phoebe, a smart, red-headed ten-year-old. He loves her, and she most wholly represents innocence to him. If Holden's feelings for Jane are shot with sexual tension, his feelings for Phoebe are purely protective. He is already reeling from his intelligent, red-headed younger brother, Allie's, death from leukemia, and he feels determined to connect with this sister. Much of his wandering in New York City is motivated by her: he buys her a record and goes to places like Central Park where he thinks he might find her. Finally, he sneaks in to visit her at his parents' apartment. When she accuses him of not liking anything, he reveals to her, as he has to nobody else, the desire of his heart: to protect children, who represent innocence, from danger:

"I thought it was 'If a body catch a body,'" I said. "Anyway, I keep picturing all these little kids playing some game in this big field of rye and all. Thousands of little kids, and nobody's around—nobody big, I mean—except me. And I'm standing on the edge of some crazy cliff. What I have to do, I have to catch everybody if they start to go over the cliff—I mean if they're running and they don't look where they're going I have to come out from somewhere and catch them. That's all I'd do all day. I'd just be the catcher in the rye and all. I know it's crazy, but that's the only thing I'd really like to be. I know it's crazy."

Jane and Phoebe represent idealized illusions of innocence to Holden, and they act as motivators to him.