[1] What I Was tells the story of a secret friendship between two teenagers, one an unhappy public schoolboy and the other living an independent and isolated life on the beach near the school.

The novel opens with the protagonist, Hilary, a sixteen-year-old boy arriving at a grim East Anglian boarding school in 1962 after being twice expelled from previous institutions.

While slacking on a school cross-country run, he meets Finn, who lives alone in a beachside shack and sustains himself by fishing and working at the market.

On one visit to Finn, Hilary realizes his friend is ill, and suspects he may have given the other boy glandular fever, which had spread through the school several weeks before.

Both schoolboys and adults misunderstand the innocent nature of their friendship, particularly when it is discovered that Finn is only fourteen, two years younger than Hilary, and is actually a girl, biologically.