"Sun! A great beam of sunlight bathes the island! Squint into the dazzle: far above, there's a hole in the roof. In that light you see beaches of white-gold sand; trees heavy with bright fruit; the reds and blues and greens of the Surface."[1]
Aestival is an island in the Unterzee, above which lies a hole in the Roof of the Neath.[2] The sunlight shining through gives it the appearance of a picturesque beach, with white sand, fruit-bearing trees, and other features evocative of the Surface.[3] Unfortunately, sunlight is both deadly and highly alluring to denizens of the Neath, and zailors who visit Aestival may lie down on the sands and smile as their life fades away.[4][5]
Given its dangers, Aestival is completely uninhibited aside from a scattering of wildlife.[6] There is evidence of past settlement, however, including a country house filled with the bones of its former inhabitants - seemingly scorched by sunlight as they were getting ready for breakfast.[7] Hidden within Aestival is a mysterious meteorite-like object: a mechanism of the Red Science. This object was a prototype launched by the Iron & Misery Company at the roof, breaking it open and letting the sunlight pour through.[8]
↑Location description, Sunless Sea"In that light you see beaches of white-gold sand; trees heavy with bright fruit; the reds and blues and greens of the Surface.""
↑Gather supplies, Sunless Sea"[...] on the way back to the ship, one of your crew topples over [...] She's smiling blissfully. "Go on, cap'n," she says. "I've missed the zun." Her eyes close. Sunlight is perilous for those who've lived in the Neath too long."
↑Investigate the ruins, Sunless Sea"There was some sort of installation here - and what looks like a handsome country house. [...] what happened to them? [...] Chairs strewn with bones - a half-dozen skeletons. [...] These people died peacefully, sitting down to breakfast, as the Surface sunlight spilled over them."
↑Seek the Iron & Misery company prototype component, Sunless Sea"Seek the Iron & Misery company prototype component [...] Days of back-breaking labour unearth a [...] a meteorite. A broken armature of steel and copper sheathes its sides. The zailors fall back before it as the glyphs on its side crawl with fire. [...] "This must be what broke the roof. [...] A Seal of the Red Science!! [...]"
