Snore. This is not an original idea. Not for the author and not for the Lovecraft-pastiche Helmut Finch: Robert W. Chambers wrote this story back in 1895 and it was called "The King in Yellow." Furthermore, the pseudo-science of memetic theory certainly predates that quack Richard Dawkins.
I don't know if it's because I despise stories about writers, or because I found the idea of a Lovecraft pastiche to be very, very well-worn ground (people were writing Lovecraft pastiche's when he was ALIVE for the love of God - "The Shambler from the Stars," "The Shadow from the Steeple" et al) but this story was DULL as dishwater.
This is another story where it's entire success or failure rests on "the big reveal" at the end (ie. the action and tension in the plot center around the revelation to the reader, not to the characters). Revelations like that have to be truly BIG and original to work; anyone familiar with Lovecraft saw this one coming a mile away.