The Trials of Apollo

Book cover titled 'The Trials of Apollo: The Hidden Oracle' by Rick Riordan. The cover features a person with dark brown curly hair in an orange shirt reaching towards a pair of large stone Greek-style columns with a blue background.
Gouache illustration of two people, one pointing at a brick wall that has white paint painted over a mural. The other in the foreground looking at the other person.
Hand-drawn illustration of a group of people sitting at a table, with one person speaking and others listening. The background is warm, with a textured orange and yellow tone, and part of a page of printed text is visible behind the drawing.
A painting of a large green and yellow snake, mythological Python, with a mischievous expression, partially coiled around a scene showing two people with worried expressions, set against a dark background with rocky borders.

Development

Sketch of a man pointing towards a sign that reads "The Hidden Oracle" and "Tales of Apollo." The background features a building resembling the Temple of Apollo at Delphi, with a small depiction of the temple on the right. The drawing includes text a
Hand-drawn sketch of a mural depicting an Apollo mission scene with a figure of a man on the left and a woman on the right, with coloured details and handwritten notes below.
Hand-drawn sketch of four people sitting at a table, engaged in conversation, with speech bubbles above them. Handwritten notes below the sketch.
A hand-drawn storyboard with four panels. The first panel is a title that says "Scene Four" and "Chapter 12" with a note that reads "Apolo eating with his kids + Nico." The second panel shows a sketch of apolo playing a game, with a note mentioning N
Hand-drawn sketch of a comic page with three panels. The top panel shows a person observing a dragon-like creature. The middle panel contains handwritten notes, including the title "New talking to Python dialogue" and a note about using dialogue to s
Sketch of a serpent at the center of the world, with handwritten notes at the top.
A sketchbook page with handwritten notes and sketches. There are dragons, a person with glasses, and a small dragon, all drawn. The notes reference "Scene ten," "Chapter 3 or," mention a character named Leo returning on a bronzed dragon, and describe
Two sketches, both depicting two men. The bottom one focusing on a man with dark curly hair with a hand reaching out to his face.