Answer:
Colin's journey into the garden helps develop plot By giving Colin a reason to improve his own health.
Step-by-step explanation:
The secret garden by Frances Hodgson Burnett tells the story of the friendship of two boys and a girl which helps each other to overcome their personal conflicts as they discover a secret garden in the mansion of one of them, this event creates a union between the three characters where they trust each other and encourage each other to be better.