In the vaults of our hearts and brains, danger waits. All the chambers are not lovely, light and high. There are holes in the floor of the mind, like those in a medieval dungeon floor - the stinking oubliettes, named for forgetting, bottle-shaped cells in solid rock with the trapdoor in the top. Nothing escapes from them quietly to ease us. A quake, some betrayal by our safeguards, and sparks of memory fire the noxious gases - things trapped for years fly free, ready to explode in pain and drive us to dangerous behavior...