According to psychologists remembering is an essential part of healing. To survive and recover one must remember and believe that the event happened. One must discuss it and express one‚Äôs emotions relative to it, understand and mourn it.The intervention on Notre-Dame must allow for this. This proposal provides both the experience of presence and absence simultaneously aiding the healing process rather than promoting collective amnesia. The mirrored glass exterior cladding reflects the skies over Paris dematerializing the roof and tricking the eye into imagining the great cathedral without a cover or spire. This provides a sad but necessary reminder of the consequences of the fire. From the nave of the Cathedral one can still witness the holes in the vaults above and is drawn to climb up and visit the new roof where the experience is reversed. Visitors can now access the space that was off-limits via a catwalk and understand the roof and spire that once stood there by reading the void of what once was. A timber structure - the inverse of the original - holds, on one side, the exterior mirrored glass cladding and on the other, the interior cladding made from lightly frosted glass. At night, edge lighting in the void shaped glass creates a ghost of the past that can be seen from far away. This flips the daytime experience and materializes what once was only to have it disappear again by the next morning.