The story opens with a 136-million-year-old pterodactyl egg hatching, and a live pterodactyl escaping through the gallery glass roof, wreaking havoc and killing people in Paris (the Gallery of Paleontology and Comparative Anatomy returned the favor by placing a life size cardboard cutout of Adèle and the hatching pterodactyl in a glass cabinet outside the main entrance on the top floor balcony).