According to Osho, the fourth stage is not an experience at all but a gap—pure, silent no-experience in which the experiencer dissolves. Nothing happens; the knower, known, and knowledge vanish. It can only be felt, never said. Any name—Brahman, nirvana, etc.—is just a provisional label, inevitably misleading before this wordless silence.
At the deepest stage, there’s only a quiet emptiness where ‘you’ and any happening disappear—felt but impossible to describe.