A habitat called the hoop was supposed to solve housing problems in a futuristic city. Something doesn't work and the hoop becomes a dumping ground for undesirables. There is a curfew for hoopers to be back in hab and out of city proper. A goth like cult called thumpers get brain implants that thumps in their head and they all silently bang heads in sequence. Not great but unique and I can't find any evidence it ever existed. Any help would be appreciated. Thanks