The Knife and the Serpent

From Hugo Award winning author Tim Pratt comes a new, high-concept space opera, exploring technology, family and the price we pay to follow our destiny, perfect for fans of Peter F. Hamilton and Adrian Tchaikovsky. Tamsin and Glenn, ordinary as anyone in the Bay Area. Tamsin is shocked when her grandmother is murdered. But the surprises keep coming when she finds out that grandma was an oligarch in exile from an adjacent universe in the Nigh-Space continuum.
Tamsin finds herself heir to vast wealth and a terrifying future, but the dimension-crossing killers out to exterminate her family are after her. Unless she gets them first. first. Now Glenn has learned that his girlfriend Vivy is a secret agent for an interdimensional organisation devoted to protecting the inhabitants of Nigh-Space from fascists, tyrants, and hostile aliens. And she's in trouble.
Glenn never imagined he'd end up in another universe on a sarcastic spaceship trying to save his girlfriend, but there he is.