Las recomendaciones de Jo Walton nunca me pueden faltar:

This is a very odd book. It’s SF set after an apocalypse and it’s about people who can travel to alternate universes, but only those where their alternate selves are dead. You know how some books are vast sweeps of epic and others are intricate miniatures painted with a tiny brush? This is the latter. [...] slightly claustrophobic, but memorable and effective and very compellingly written.