Just finished Dan Simmons' "Song of Kali", about a journalist's descent into personal (and physical) hell during a few days in Calcutta.

It's a terrific little novel. The star is Simmons' evocative description of the city itself, with its chaotic sounds, smells, sights, pervasive poverty and degradation, violence. But what stuck with me was the central premise, that cities like Calcutta are like black holes of misery and violence -- of evil -- that rend the very fabric of space and time and pull visitors into their orbit in order to spread that evil.