Nook

"A gap in this colossal sea monster's throat has been forced open with thick heartmetal beams. They strain under the pressure, but hold. As you pass through, your zubmarine lights pass over a message carved in a floating piece of some unfortunate's hull. BEYOND IS NOOK. BEYOND IS FREEDOM. BEYOND IS- The rest is scratched out."

Nook is the name of a large creature embedded under the zee.

A Taste of Freedom

"Many have come here from London, the Khanate, the Presbyterate; abandoning cultured life for this tenuous existence. They grin, their mouths full of stolen flesh, or float naked and carefree. Many have nothing, and nothing to lose."

Despite the obvious hazard of living inside a giant, lamprey-like, parasite-infested beast whose mouth is kept open only by heartmetal beams, Nook is decently populated with people from all across Unterzee. The inhabitants of Nook have dodged the bloodthirsty parasites and hollowed out some of its myriad teeth to form caves and houses.

Conveniently, the water inside Nook, while foul, is actually breathable. Newcomers will usually find their lungs unaccustomed to breathing the water, and after a period of time they might feel as if they are being drowned. Getting drunk tends to be the easiest cure for that sensation.

Nook changes the people who live in it, causing them to lose their inhibitions and become more violent. Most of its denizens are naked; visiting Nook in a full diving suit is the fastest way to ridicule. Repeated visits to Nook can make clothing feel rather stifling - let alone living there.

The only source of light within the beast is the strange green polyps that the inhabitants mine from the teeth. As one might imagine, they're fiercely fought over, especially by those who seek treasures deeper in Nook's lightless belly.

There's an etched tooth-house in the upper cavities that is filled with air pockets. This allows for activities, like talking, that wouldn't be possible in the breathable water. The house is maintained by a Flinty Latitudinarian who "cares not a damn" about whatever might be happening outside of Nook.

The Leviathan

"Are you quite sure you want to know this?" Beyond this point lie major spoilers for Fallen London, Sunless Sea, Sunless Skies, or Mask of the Rose. This may include endgame or major Fate-locked spoilers. Proceed at your own risk. You can find out more about our spoiler policy here.

"Once, you surged between the suns. You recall swelling suns, and golden thrones, and the writhing world of Now you coil in this pit on the bed of this little sea and sleep and dream of the winds of nowhere and stir and sleep again. You are growing hungry."

Nook originated from the High Wilderness, where it hunted between the stars. Under special circumstances, one might be able to see the beast as it was in the skies. Nook may in fact be an Aeginae, the same species as Storm, as their inhibition-eroding, violence-inducing effects are similar.