A high-quality hentai anime screenshot illustrating the theme "Secret Visit to the Royal Alchemist's Laboratory." Inside the dimly lit laboratory of a stone castle, the royal alchemist is fucking a young queen—who wears only a golden diadem—deeply from behind. The royal alchemist, dressed in a black velvet Renaissance-style doublet with padded shoulders, thrusts vigorously with his massive, erect penis into the queen's anus. The queen's face wears an expression of dazed ecstasy, her large anime-style eyes wide with arousal. In the foreground, a sharp close-up reveals a glass vial containing a chemical substance resting on a wooden workbench, the handwritten label "viagratus" is clearly visible. The background is cluttered with potions and old grimoires. Vivid colors, crisp linework, and a high-quality anime style.