Eight tall plane trees spurt out of the granite paving on Place Saint-François. The many passers-by probably do not realise that under their feet, the giants’ roots spread almost as far and as deep as their branches. 

This underground network, essential for the trees’ vital flow, rubs shoulders with the city’s network. A labyrinth of pipes, tubes, electrical and communications wiring and heating ducts that leaves very little space for plants. In the heart of this invisible entanglement, a sufficiently generous space remains in open ground to host a ninth tree. 

It is in this perimeter that after nightfall, the ghostly portrait of the ninth plane tree is projected — at night, since although there is still a little space underground, the surface is too cluttered by human activity during the day to host a tree or a garden. The abstract, projected portrait features both the crown and the root system of the plane tree, like a mirror effect that reveals the duality of the soilless beauty of a verdant tree as well as its subterranean complexity.