London, 1850. The Great Exhibition is being erected in Hyde Park and among the crowd watching the spectacle two people meet. For Iris, an aspiring artist, it is the encounter of a moment – forgotten seconds later, but for Silas, a collector entranced by the strange and beautiful, that meeting marks a new beginning. When Iris is asked to model for pre-Raphaelite artist Louis Frost, she agrees on the condition that he will also teach her to paint. Suddenly her world begins to expand, to become a place of art and love. But Silas has only thought of one thing since their meeting, and his obsession is darkening ...