"Codex: a desperate caveful of mute exiles, and an inexplicable colony of shivering, bad-tempered monkeys."
Codex is a chilly island between Whither (to the far north of London) and Avid Horizon, the northern edge of the Neath. It is indeed home to a group of mute exiles and a band of grumpy monkeys. Interesting.
Some of the exiles have a certain question, one whose answer they've been searching for for years. If they find the answer to this question, they will start speaking again, but only to complete their library information on the answer. Even more interesting.