Fantastic (in every sense of the word) collection of short stories from the British Library. It was mentioned (by @unwisetrousers on Twitter/X) that it contained a John Buchan short story (Space) so being a Buchan fan I ordered a copy. The Buchan story is a not unexpected excursion into the scientific/mystical world (after all he authored "The gap in the curtain" which has the same narrrator (Sir Edward Leithen) and which covers similar ground. Delighted it also includes Heinlein's "...and he built a crooked house" (which read in my teens and have never forgotten) as well as H G Wells "The Plattner story" (misquoted as 'The Plattner experiment" in Sayers short story "The image in the mirror"), Borges' "The library of Babel" and a work co-authored by H P Lovecraft (The Trap). Whilst the stories are linked by the idea of mathematics, they stray into SF and horror. Recommended for lovers of SF and horror. ( )