Edouard Manet is an infamous painter in 19th century Paris. Emily Porterfield is a conservator of paintings in 21st century Chicago. He made her fall in love with art when she was nine years old and yet Emily was the muse of Edouard's greatest artwork 150 years before she was born. Their story begins with a letter. While x-raying a painting for an upcoming Edouard Manet exhibition at the Art Institute, Emily stumbles upon a hidden letter painted in lead white beneath the layers of oil and varnish. Through the mysterious properties of the letter, Emily is raptured to the past where she becomes the muse who influences Manet's greatest works. As their relationship grows between each new letter and she discovers that his confusing iconography can finally be explained through their story, an underlying plot of murder and art forgery is uncovered in the present. With the exhibition gala approaching, a connection between the murderer and the forgeries reveals itself and Emily is forced to ask how their love can withstand the test of time when only a few letters remain.