Watch Imagine online: Episode 3 The Plinth, the Model, the Artist and his Sculpture

In 2005, an extraordinary sculpture by leading Brit artist Marc Quinn of a naked, heavily pregnant, disabled Alison Lapper was unveiled on the empty fourth plinth in Trafalgar Square. It's a project that's been dogged with controversy. Following the creation of Alison Lapper Pregnant over five years, this film tells the compelling story of how two very different people came together to challenge preconceptions about beauty and what is considered normal.

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