Sometimes in the mornings, after incantations, Colin gives Magic lectures to practice for when he's an adult and must speak about his "great scientific discoveries." As Colin speaks, Ben Weatherstaff watches him critically and notices how healthy Colin is starting to look. When he comments on Colin's appearance one morning, Colin insists that his experiment is succeeding and Magic is working. The children weed and Colin declares that Magic is most effective when a person moves their body.
The assertion that Colin will continue to give these lectures as an adult reminds the reader that the whole purpose of learning what Colin and Mary are learning about nature and Magic is first to heal oneself, and then to pass it on so others can also heal. This again suggests that the power of positive thought comes from how a person applies it to others.
A bit later, Colin stands upright and shouts for Mary and Dickon to look at him. He says that he suddenly realized he's well. He announces that he's going to live forever and make Magic, and says he wants to recite something joyful and thankful. Ben Weatherstaff grunts that Colin might consider singing the Doxology. Colin has never heard of it before as he's never been to church, but Dickon instructs Colin and Ben to take off their caps and stand up. Then, he sings the Doxology, which praises God. When Dickon finishes, Ben watches Colin closely. Colin deems the Doxology just the right thing and wonders if Magic and God are the same thing. Everyone sings the Doxology again and Ben tears up: suddenly, the Doxology has meaning for him.
The Doxology links Magic directly to religion, as it's a classic Christian hymn. However, because Colin has never been to church, the Doxology is simply a way for him to give thanks and understand that positive thinking transcends faith traditions. In the case of Ben Weatherstaff, hearing the Doxology in this pastoral setting rather than in the pews allows him to find meaning in his own faith, which appears to have been wavering. This suggests that the garden has the capacity to teach Ben things, too.
Looking startled, Colin looks across the garden. A woman lets herself in through the garden door and Dickon explains that it's his mother, Mrs. Sowerby. All three children run to her and Colin shyly tells her that he's wanted to see her from the minute he learned of her existence. Mrs. Sowerby seems overtaken by emotion and explains that this is because Colin looks so much like Mrs. Craven. Colin asks if this will make Mr. Craven like him, and Mrs. Sowerby assures him it will.
Colin's outright admission that he's wanted to meet Mrs. Sowerby reminds the reader that what Colin (and Mary, for that matter) craves now that he's found friendship is a parent figure. Though Mrs. Sowerby isn't Colin's parent, she can still play a parental role by speaking to Colin in an affirming way.
Ben Weatherstaff approaches and points out Colin's strong legs to Mrs. Sowerby. Mrs. Sowerby then turns to Mary and says that with how well she's looking, she'll look as pretty as Mary's mother and will be "like a blush rose" when she grows up. Mary is pleased to hear this, as she always thought her mother was beautiful. Mrs. Sowerby then tours the garden and admires the plants. Both Colin and Mary feel warm and understood and choose to tell her about Magic. Mrs. Sowerby agrees that she believes, though she's never known Magic by that name. She suggests that "th' Big Good Thing" is all the same, and people can call it what they like.
While the reader knows little about Mary's mother, Mrs. Sowerby's words to Mary suggest that Mrs. Sowerby actually knew Mary's mother and further, that she might not have been as bad of a person as Mary's isolated childhood would lead one to believe. This reminds the reader that people are complex and can contain both good and bad.
Colin says that he feels joyful, and Mrs. Sowerby says that the Magic listened to the Doxology. Then, she pulls out a basket with a feast inside. They laugh and talk and Mrs. Sowerby laughs especially hard when she hears how difficult it is for Mary and Colin to pretend that Colin is still ill. Mrs. Sowerby assures them that Mr. Craven will come home soon. They talk about visiting Mrs. Sowerby's cottage and finally, they all prepare to leave the garden. Before Colin sits in his wheelchair, he stands in front of Mrs. Sowerby and tells her that he wishes she were his mother. Mrs. Sowerby pulls Colin into an embrace and assures him that Mrs. Craven is here, in the garden.
By assuring Colin that his mother's spirit exists in the garden, Mrs. Sowerby helps guide Colin further in the direction of coming to terms with his mother's death. This allows him the emotional skills to look for mothering figures in more places, while also pointing him in the direction of the parent he still has. Her insistence that Mr. Craven will come home soon offers another place in which positive thinking may have an effect on someone other than the person doing the thinking.