Oceane, a graphic designer in London, is all but agoraphobic: When she wants to experience Finland, her travel agent imports some Finns to her place for a dinner party. Years ago, while performing at a live sex show in Barcelona — ”Writhing about in ecstasy is harder work than you would credit” — she dated Walter, who later died. Imagine her surprise when she starts getting letters from him. To sleuth this out, she seeks the assistance of Audley, whose usual line of work raises debt collecting to an art of pain. The proper response to all of this is Wha? Fischer, author of 1992’s acclaimed ”Under the Frog,” has whipped up a tall tale about home and distance that, though nattily surreal, often trips over its own cleverness.