This book falls into a weird genre gap between SF and slash. As SF, it is less than fully satisfying, because the bafflegab fails to fully persuade, and as slash it is less than fully satisfying because it doesn't hit the emotional beats that comprise the genre's backbone. So... I'm going to kind of give it two reviews.

SF: The technology of 'mnem' is a sort of cross between VR and dreaming; it provides an immersive, persuasive experience to order, but afterward you won't be able to recall it. For reasons (?) people pay for this experience they can't remember.

The protagonist, Daniel, owns a mnem parlour that isn't doing well since he stopped making his own mnems for customers. He stopped, because his father had a bad experience with a mnem he made, and now cannot be made to remember that his wife left him five years ago. Daniel gives his customers cheap serbian mnems, and in one of them, he encounters a visitor who shouldn't be there.

There are two mysteries; how did Daniel's father have a persistent mnem, which goes against the thing's very definition? And how is someone else visiting their clients' mnems?

The story doesn't answer the first, although a character does point out that persistent mnems could overturn the market; presumably this is addressed in the second and third book of the series. The answer to the second leads into the second genre.

Slash: The visitor in the mnems is Elijah, with whom Daniel has an initially promising but ultimately unsatisfying encounter which Daniel at first believes was a fluke of the mnem. When Elijah reappears, Daniel is sent on a search to discover if he is some kind of artifact of Daniel's own loneliness, or a real person impossibly trespassing.

When Daniel finds Elijah in the real world, he learns that Elijah is on the autism spectrum, and prefers to interact with people in mnems where he can understand people directly without the confusing interface of language.

If this were fanfic, Elijah and Daniel would realize they want to be romantically (and sexually) involved, and together solve the mystery of Daniel's father. Instead, Elijah makes out with Daniel once, and leaves, leaving Daniel confused about whether the encounter even occurred in waking reality.

So my real problem with this book is that it is not a book by the definition of either genre. It is, I assume, 1/3 of a book. But I'm not paying money for the other two in the series to find out, because I'm so peeved by the failure of this book to fulfil the contract with the reader. I realize no contract was signed, but isn't genre a kind of implicit contract?

Also the attempt to make the 'mnem' technology failed on me completely because Daniel persisted in talking about building it with 'pixels', which, if there is any direct-to-brain transfer technology, it had by god better not use pixels.