The next week is rainy and Colin catches a cold, but he remains in good spirits. Dickon visits daily to talk about what's happening on the moor and to tell Colin and Mary about all the animals building nests and burrows. Most exciting to talk about are the plans the children make to transport Colin secretly into the garden. As the days pass, Colin becomes certain that the garden must remain a secret and that people must think that he's just going out with Dickon and Mary for fun. They devise a path to take and one day, Colin summons Mr. Roach to his room. Mr. Roach has never seen Colin, so he's curious to lay eyes on the boy. Mrs. Medlock tells the gardener that things are changing for the better and warns him that he'll probably see Dickon in Colin's room.
The fact that the children take such delight in planning Colin's excursion into the secret garden—and specifically, keeping it a secret—reminds the reader that for Colin and Mary, the secret is at least half of the fun. It allows them to practice being independent in a place where there's little risk of getting hurt or things going wrong (as Colin isn't actually ill). When Mrs. Medlock says that things are changing in a good way, it shows that though she's not as plugged into the natural world as the children, she still benefits from their positive thoughts and engagement with nature.
Upon entering, Mr. Roach is a bit surprised to see Dickon and a variety of animals sitting with Colin and Mary. Colin looks Mr. Roach over haughtily and tells him that he's going to go out in his chair. He says that the gardeners need to leave the area until he gives the word that they can return to work. Mr. Roach is relieved that Colin isn't asking him to cut down trees and almost laughs when he leaves the room. He and Mrs. Medlock laugh that if Colin lives and if Mary stays, he'll learn that the world isn't his alone.
Mr. Roach's conversation with Mrs. Medlock mirrors the one that Mrs. Medlock had with the doctor, which suggests that most of the adults at Misselthwaite understand the power that children have to shape each other's behavior. This suggests that they all knew these steps that they could take to improve Mary and Colin before the children found each other; they just chose not to take them.
Dickon returns to the garden, while Mary stays with Colin. During lunch, she notices that his eyes are especially big and asks him what he's thinking about. He admits that he's thinking about spring for the first time, and on the morning that Mary announced spring's arrival, he imagined a procession with music. Mary says that it feels like a celebration outside.
By ascribing a human event like a procession to a natural one like the coming of spring, Colin tries to merge what he knows from his books with what he's learning about the outdoors.
Later, the nurse gets Colin ready. Dr. Craven tells the nurse that he wishes she could go with him, but the nurse refuses to spoil Colin's good mood by insisting on going. A footman carries Colin downstairs, arranges him in his wheelchair, and Dickon begins to push the chair outside. Colin looks at the sky and breathes in deep breaths of air.
This time, when the nurse insists upon following Colin's orders, she's doing it for the good of her charge. Again, this shows that Colin's transformation is helping other people be better and kinder too.
They wind along through the garden and when they approach the path by the ivy wall, they all start to whisper. Mary points out landmarks along the way—where the robin showed her the key and where Ben Weatherstaff works—and then, she steps into the bed, opens the door, and Dickon pushes the chair into the secret garden. Colin gasps happily and looks at all the growing things. Dickon and Mary watch Colin's face, which starts to take on some color, and Colin shouts that he's going to get well and live forever.
Just as with Mary, Colin gets color in his cheeks on his first day outside—this reinforces that the natural world begins healing a person immediately. When Colin declares that he's going to live forever, it speaks even more to the healing power of nature, as this optimistic thought has never crossed Colin's mind before.