How much grief is too much? How far should we go to avoid pain? From the author of the international bestselling novel Agatha comes a literary thriller about grief, love, science, and societal norms. A Danish university research group is finishing its study of a new medicine, Callocain: the world's first pill for grief. But psychology professor Thorsten Gjeldsted suspects that someone has manipulated the numbers to hide a disturbing side effect. When no-one believes him, he teams up with two young students to investigate: Anna, who has recently experienced traumatic grief herself, and Shadi, whose statistical skills might prevent her from living a quiet life in the shadows. Together, these sleuthing academics try to discover what's really happening before the drug is released to the entire population. Blue Notes is brimming with ethical and existential ideas about the search for identity and one's place in the world, while offering a highly original literary adventure that ultimately underscores the healing power of love.