"... You want to know why you are all here? Because, frankly, you chased a Cat. A terrible, disgusting, awful Cat that should be put down for what he does, but so it goes."

That is the short answer. Now for the longer one.

"The long answer is that this World seeks out those who are... abnormal, in some fashion. Ill, others might say. Look around you. Out of all the Hearts you have been in, can you say anyone here has been entirely well mentally? ... Well. Perhaps that has something to do with it. The World wants something like itself. It likes to build the sort of vistas of these people. Normally its chaos would be prevented, but... you know. My keys. He stole them."