Decamps fascinated his contemporaries: largely self-taught, he was celebrated for his imagination and freedom from academic constraints. The story is from the "Book of Tobit": Tobias was sent on a long journey, his travelling companion an angel. Here, at the angel's direction, he captures a strange fish whose guts will free his future wife of a demon and restore sight to his blind father. The subject allowed Decamps to explore the landscape setting: shimmering with light, we seem to sense the very air itself. Taking inspiration from the Old Masters, Decamps was intrigued with the means of painting and acutely sensitive to the properties of his materials. This study was made for a larger work, since lost.