I recently dug out a book for reading on the train. It is a book of shorter fictions of C. S. Lewis, called after the longest portion inside: The Dark Tower. The name is taken from the Robert Browning poem, just as with Stephen King but is rather different; drawing little inspiration from Browning. The tale is unfinished, only just saved from the bonfire. Its authenticity has been questioned; but I do not wish to explore that question here.
It is a science fiction story of a device: a 'chronoscope' that gazes through time as a telescope gazes through space. This is not the story of its invention; it is not set in a laboratory, but the rooms of a Cambridge college as the device is exhibited for the first time to the scrutiny of fellow academics - both scientists and other interested parties. It is narrated by a fictional Lewis, as one of the academics viewing the dreadful world of 'Othertime'.
This is ambiguously an alternate reality or something set in a distance future. The titular Dark Tower is either a replica or a shadowy reflection of Cambridge University Library (an imposing enough building in its own right). The residents, as it eventually emerges, are reflections in their own right - most prominently one of the research assistants: his reflection being one of the sinister, unicorn-like 'Stingingmen'. The whole thing is distinctly oppressive and otherworldly: different to Lewis's other works, almost a work of horror fiction.
It occurred to me in re-reading it that the whole thing had an air of the stories of M. R. James. James is known for his ghost stories: 'The Treasure of Abbot Thomas', 'Casting the Runes', 'Count Magnus' and 'Canon Alberic's Scrap-Book' notable among them. The Dark Tower is somewhat like them: the largely male cast; the Cambridge setting - for both being in a medieval setting and an academic one, the detached tone; the nature of the 'chronoscope' - which might almost be an enchanted mirror. The whole thing makes one think of M. R. James writing not just horror or short stories, but making a start at a science fiction novel.
Worth a look? If you enjoy Lewis already, perhaps. The sinister and nightmarish tone is perhaps slightly lurid - but is perhaps pervasive.