When Miri and Adam visit César, their friend receiving care at home, they can’t believe their eyes. He’s just been given Fly, a tiny robot fly. Incredible! From now on, César will be able to follow his two friends’ adventures up close! So when Miri and Adam go with their father to the opening of Aigle, a mysterious artist, César, and Fly join in the adventure. Why is La Ronce, their concierge, always in their way? Who is really behind this creator who gives a second life to waste materials through his art? Why does he never show his face? And why are some of his exhibited works so disturbing? Miri, Adam, and César — with Fly’s help — decide to investigate. But when clues, suspects, and twists start piling up, everything gets tangled… and the adventure takes a completely different turn.