London. 1850.

The greatest spectacle the city has ever seen is being built in Hyde Park, and among the crowd watching 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 . . .