Den Underbara Spegeln

On a blazing June day in the Berlin of 1950, as imagined in 1914, a lieutenant arrives in suspiciously high spirits, a will is read, and a plan takes shape to build a giant mirror for a telescope on a volcanic island. Otto Witt's early Swedish science fiction mixes inventions, a theft, a mysterious parcel and a ghostly voice.

Summary written with Claude Opus 5.5.