Tom Crick, fifty-two years old, has been history master for some thirty years in a secondary school in Greenwich, in a sense the place where, in a world that sets its clocks according to Greenwich Mean Time, time begins. Tom has been married to Mary, for as long as he has been teaching but the couple have no children.
The students in Toms school have grown increasingly scientifically oriented, and the headmaster, a physicist, has little sympathy for Toms subject. One of Toms students, Price questions the relevance of learning about historical events. The youths scepticism causes Tom to change his teaching approach to telling tales drawn from his own recollection. By doing so, he makes himself a part of the history he is teaching, relating his tales to local history and genealogy. The headmaster tries to entice Tom into taking an early retirement. Tom resists because his leaving would mean that the History Department would cease to exist and be combined with the broader area of General Studies.
Toms wife is arrested for snatching a baby. The publicity that attends her arrest reflects badly on the school, and Tom is told that he now must retire. Tom uses his impending forced retirement as an excuse to unfold a story to his students. The bulk of Waterland is devoted to this story that, before it is done, covers some three hundred years of local history and relates it to the broader historical currents of those centuries. The primary plot of the story has to do with Toms relationship to Mary both before and after their marriage. She is reared on a farm close to where Toms father, a lock-keeper, lives with his two sons in the lock-keepers cottage, beside a tributary of the Great Ouse. Tom's mother dies when he is eight years old. Mary is also reared by her father because her mother died giving birth to her. He sees that his daughter receives a strict religious upbringing. As Mary matures, her interest in men grows, and she and Tom slip into an affair and she discovers that she is pregnant. Toms brother Dick asks Mary if he is the father of the child. Mary lies to him, telling him that Freddie Parr is the father. Dick, distraught at this information, struggles with the drunken Freddie, who cannot swim, and pushes him into the river. It is Toms father who pulls Freddie from the sluice, not realising that his drowning is anything but accidental, as the coroners inquest finally finds. Mary tries to provoke a miscarriage but fails, so she and Tom, the father of the child, go to an old crone, who performs an abortion that leaves Mary sterile. Her father forces her into seclusion, and for three years she remains isolated. Finally the two fathers agree to bring their children together again; unknown to them, Tom, away fighting in World War II, has already written to Mary. When he comes home, the two marry, and Tom begins his teaching career while Mary takes a position in an old persons home. Finally, she steals a baby and explains the new arrival to Tom by saying that it is a gift from God. Obviously disturbed and suffering from a pain that has been festering since her teenage abortion, Mary is arrested.
A secondary plot involves Toms mothers family, the Atkinsons, who have run a brewery for several generations. This subplot is interwoven into the development and resolution of the primary plot.
The abovementioned work made use of the following tropes:
- The Alcoholic: Freddie's father.
- Asshole Victim: Freddie Parr isn't very sympathetic, given how he seems to enjoy bullying his friends.
- Baby Be Mine: Mary is infertile and cannot quite cope with that fact, leading her to kidnap someone else's baby. Tom convinces her to give it back though.
- Bigger Is Better in Bed: Subverted. Dick is absurdly well-hung, but it turns out to be too large for Mary to fit it in.
- The End Is Nigh: Price started a whole school club dedicated to spreading fear over the end of the world.
- Florence Nightingale Effect: How Henry Crick fell in love with Helen Atkinson.
- Four-Temperament Ensemble: Two of the temperaments are used to describe and contrast the Cricks and the Atkinsons; the Cricks are phlegmatic, passive people who've lived all their lives by the water, under the service of others, and the Atkinsons are sanguine, the go-getters who bring fortune to the Fenlands. Ernest Atkinson is more than once described as melancholic.
- Good Girls Avoid Abortion: Deconstructed by Mary.
- Ikea Erotica: Invoked to show the innocent curiosity of Henry and Mary.
- In Medias Res: The entire book jumps from place to place every chapter. In fact the whole thing ends with a flashback.
- Jerk with a Heart of Gold: Price enjoys undermining Tom's lectures, but also likes him as a teacher because of his unorthodoxy and tries to stop him from getting fired.
- Meaningful Name: Dick and Ernest.
- Murder the Hypotenuse: Dick kills Freddie because Mary leads him to think that Freddie's the one who impregnated her, so she could protect Tom.
- Parental Incest: Helen Atkinson has regular sex with her father Ernest out of pity (and maybe genuine love) for him, and agrees to conceive his child, who turns out to be Dick.
- Replacement Goldfish: Mary uses her work with the elderly and possibly her adoption of Paddy, the golden retriever, as relief from the knowledge that she can never have and nurture a baby.
- Rule of Symbolism: Mary's name is a Shout-Out to both Mother Mary and Mary Magdalene.
- The Scapegoat: Freddie gets blamed by Mary for impregnating her.
- Stupid Sacrifice: A very, very rare example that is actually done well. Dick Crick, who is mentally challenged and brutally traumatized from having killed someone, and finally out of his unrequited love for Mary, drowned himself in the belief that he was sacrificing himself for her. May double as Driven to Suicide.
- The Talk: Dick asks where babies come from, and Henry hesitates a lot before simply saying that they come from "love". A short while later Mary tries to explain sex to him, but he doesn't get it and thinks loving someone is enough to have a baby.