Following many visits to the Toulon opera house, I noticed that the accumulation of time plays an important role in this building and its interior. Starting from this characteristic point, my research follows two main approaches, a mixture of drawings and writings. The first approach is based on technical and objective observation; the second on personal and subjective observation. This observation work aims to highlight the mix of different layers of elements from the past and present in a space, over time. It offers readers the chance to journey into the potential mystery of the shadow, between two folds of a curtain.