This is a story of a meeting, or more exactly of a confrontation, between one material, water, and another material, petroleum. From essential material to fossil material --a duel between two resources of extreme political importance. From the outside, the object resembles a black cylinder 5 m in diameter by 5.5 m tall, half water cistern, half giant oil drum, that is entered and left through two holes cut in the sides. this is a "passage" into a well of infinity, a dilemma of depth. the walls inside are entirely lined, on one side, with video screen, and, and on the other, with a mirror. The screen shows a standing wave reflected in the wall mirror in an endless loop. At the top of the cylinder is placed a white mirror that reflects the infinite above. On the floor, a mirror like black oil shows another infinite space below. Finally, a transparent footbridge traverses the cylinder, abutting with the wall mirror approximately a meter off the ground. Hence the duality is total: Black/White Water/Oil Floor/Space North/South