In this short story, Stevens introduces us to her narrator Blaisdale who, after dining with a detective friend, encounters the strange Dr Frederick Holt. Holt, as part of his researches into colour microphotography, has unveiled a previously unseen world of “centipedish things, with yard-long bodies, detestable, furry spiders that lurked in shadows, and sausage-shaped translucent horrors”. In fact, at face value, the plot reads very similar to Lovecraft’s From Beyond. Indeed, it’s not a huge assumption to believe that Stevens was inspired by Lovecraft’s tale when she wrote hers.

Yet, like many assumptions, it’s completely incorrect.

More info here - https://pietersender.wordpress.com/2020/05/19/readings-unseen-unfeared-francis-stevens/