In 2010, Kadist Art Foundation, David Roberts Foundation and Nomas Foundation successively presented an exhibition of the work of Etienne Chambaud in collaboration with Vincent Normand: The Siren's Stage / Le Stade des Sirènes. For this project, Etienne Chambaud made The Exchange (The Horse). A contract was written with the lawyer Daniel McClean to establish the conditions for the exhibition and conservation of copies of the sculptures exchanged between the collections of these three foundations. The copies become the new originals that can never be exhibited and must remain preserved in sealed crates. The contract, as well as other documents such as the proof of authenticity or the bailiff's declaration regarding the sealing of the crates, constitute the only visible part of the work as evidence of its existence, while also defining its absence.