I'm looking for a sci-fi novel/book about a planet of people who kill in their minds but are otherwise very pacifist.
There are, I believe, three people who are stranded on an unknown planet. They make their way to a wall surrounding a city of people who at first glance appear to be pacifists, but as the crew stay longer and learn that the pacifist inhabitants plug into the wires within the city walls to act out the most gruesome and violent acts against their fellow inhabitants. Within the walls is the key, while the space travelers are unable to leave. This is an older sci-fi novel; Isaac Asimov-type stuff.