There are two key (and related) incidents in the first book, where Eustace establishes some sort of independence. The first concerns Miss Fothergill. Miss Fothergill is an old lady pushed around in a bath chair, whom they both - but Eustace in particular - find repulsive, not least because of her twisted arthritic hands. Hilda persuades Eustace to speak to her which he, reluctantly, does. She turns out to be a pleasant old lady and invites Eustace to tea. He accepts, though not without trepidation. The second incident occurs when Nancy Steptoe (for whom he has a soft spot) invites him to go on a paper chase at the same time as his tea invitation. He goes with Nancy but they get lost and wet. Eustace, who is of delicate health, becomes very ill but he is rescued by Dick Stavely, son of Sir John and Lady Stavely, some five-six years Eustace's senior. Eustace hero-worships Dick but soon finds out that Dick is more interested in Hilda. He does go to tea with Miss Fothergill later and assumes a regular relationship with her, which nets him £18,000 when she dies.
In the next book, he is in Oxford, while Hilda has set up a clinic for handicapped children, which she is running, with some financial help from Eustace. Not a great deal happens, except that Dick moves closer to wooing Hilda and Eustace struggles with his independence. The book is mainly setting the scene for the final book. Eustace is spending the summer vacation with Lady Nelly Stavely (Sir John's sister) in Venice and first pretending to and then actually writing a book (which is accepted for publication near the end of the book.) He hears various reports of Hilda from home, most of which are discouraging and many of which cause him distress. In short, it seems she is engaged to Dick Stavely and then is not. She also seems to be having trouble with the clinic. Near the end he is summoned home to find that Hilda's has had a nervous breakdown after Stavely broke off the engagement and is paralysed. Of course, by a certain amount of trickery but to his own detriment, he saves her.
Of course, this only touches the surface. Hilda's and Eustace's sister, Barbara, their aunt Sarah, their father, other Stavelys and other characters make for a rich portrait of England after World War I, even if it is the well-to-do England with the poor totally excluded. But as with The Go-Between, we get a fascinating story of someone who is not in the picture, who sees things happening without realising what they really mean but who is eventually caught up in them all without being aware, till it is too late.