A luminous portrait of love in its many forms--yearning, obsession, addiction--and just how messy and destructive it can be

Robin is unreliable, unstable, and utterly devoted to his oldest friend Henry. So when Henry's beloved mother--the lauded novelist Marian Finch--dies unexpectedly, Robin is there to pick up the pieces. Henry comes into possession of a venerable antiquarian bookshop and there--for a time--they build a life, with their found family of sorts.

But grief can send us down unexpected paths. For Henry, it leads him to the theory of multiple universes and to Yolanda, a brilliant scientist who can help him understand it.

Robin and Yolanda have three things in common: they are in love with the same man, they despise each other, and they are oblivious to the fact that Henry is spiralling into a dangerous obsession that will irrevocably change them all.