The Great Believers by Rebecca Makkai:
Fiona had wanted to trick her parents, to exchange Nico’s ashes with fireplace ones and give the real ones to Terrence. It was hard to tell if she was serious. But Terrence wasn’t getting any ashes, and he wasn’t getting anything else either, besides Nico’s cat, which he’d taken when Nico first went into the hospital. The family had made it clear that when they began dismantling Nico’s apartment tomorrow, Terrence would be excluded. Nico had left no will. His illness had been sudden, immediately debilitating—first a few days of what had seemed like just shingles, but then, a month later, moon-high fevers and dementia.