Nine layers of sky - Liz Williams

A former Soviet rocket scientist, Elena Irinovna now cleans office buildings - until she crosses paths with Ilya Muromyets. A remnant of Russia's glorious and fabled past, Ilya is an eight-hundred-year-old turned heroin addict, dreaming of a death that never comes. They are brought together by a strange artefact Elena has found, which offers a glimpse into another dimension, creating a dangerous breach in a world Elena only thought she knew.

Ilya is no stranger to the unexplained. He's been hired by a mysterious organization to track down the artefact. But nothing prepared him for what it offers - or for a woman like Elena. Fighting their own inner demons as well as those from across the breach, Ilya and Elena embark on a harrowing trip between nations and worlds. And for the first time the man of myth and the woman of science discover that they have a dream to defend - and even die for.