When devil-may-care- teenager, Tansy Helliwell decides to take the rap for breaking George Haythorne’s greenhouse, she little realises the path she has set herself on. Simultaneously, her grandmother is killed when a stone is thrown into her garden. Tansy’s sister, Elise, accuses her of being responsible and she retaliates by breaking her grandfather’s illusions as to her younger sibling’s innocence. In granddad’s distress, he declares that the world in not a fit place for children little realising the effect this will have.
Having befriended George, Tansy wants to garden and proposes making lily ponds on his allotment. She falls into the stream there and, when she discovers that Elise’s best friend, Marie Adour, has been washed away by the River Ure at the very same time, this second coincidence shocks her. Feeling she must be responsible, she vows to bring consolation to Marie’s parents.
Her ponds are now to be a garden of remembrance but events conspire against this. She dubs herself the ferry girl but this only seems to bring her more and more passengers. First there is George himself, whose wife was lost on the Herald of Free Enterprise. Next she meets Evelyn Baldwin, a member of the Disassemblers, a cult whose rites involve smashing glass portals and then fleeing. Evelyn falls in love with Tansy and endeavours to improve her speech and manners. However, it transpires that her partner was killed in an avelanche. Tansy also meets Deidre Neville, the lady of Ockleston Hall, who together with her husband, Raymond, owns the allotments. She desperately wants a child. Almost lastly comes Dermot Reeves, an arch-criminal who has chosen Tansy as his girl. She finds herself under his protection and when she reaches 16, succumbs to his entreaties, only to discover he is impotent.
All these people need her help but what can she do about it?
To make matters worse, as a result of Tansy’s meddling, her family is falling apart. Also the Nevilles are intent on building water gardens themselves and to finance these, the allotments are to be developed as executive housing.
Tansy often despairs but refuses to give up; even when her bringing of her grandfather and Gabrielle, his childhood sweetheart, together results in her becoming pregnant. This shocking occurrence is the catalyst that brings the plague of infertility to an end. Gabrielle dies in childbirth and Tansy ensures the baby girl is named Marie,
It seems that Tansy is not to witness this new generation. Because Deidre believes in her, she allows her to wear her precious diamonds for a photo shoot with Helen Chung, a top photographer, and, after the Disassemblers have struck, she is abducted. At the same time, Marie is orphaned and Mandy, another cult member, carries off the abandoned child. Mandy is a poor down-and out woman who longs for Dermot’s love and it is she who awakens his conscience, so that he, at the last, agrees to pay the necessary ransom.
After her release, Tansy is shaken and traumatised but has work to do before surrendering herself to the police: she rescues Marie but knows she has given herself the additional burden of recovering the diamonds.
How is she now to carry out all her promises? There is only one reason she can succeed - because she is the ferry girl.