In crystals of the title compound, C(23)H(23)N(5)O(3)S, the indole system is planar and the phenyl ring of the phenylsulfonyl group makes a dihedral angle with the best plane of the indole system of 77.18 (4) degrees. The olefinic bond connecting the azabicyclic and indole systems has Z geometry. The geometry adopted by the C=O bond with respect to the N-N bond is trans. The O atom of the carbonyl group of each molecule is hydrogen bonded to the hydrazidic H atom of an adjacent molecule to form an eight-membered-ring dimeric structure.