How to be Luminous is a lyrical and engrossing story about the aftermath of tragedy and the power of self-belief and love. Harriet Reuter Hapgood's beautiful writing radiates with colour.

When seventeen-year-old Minnie Sloe's mother disappears, so does her ability to see colour. How can young artist Minnie create when all she sees is black-and-white? Will her mysterious ailment – and grief – stop her from following in her mother's footsteps and becoming a famous artist?

Middle child Minnie and her two sisters have always been able to get through anything together – growing up without fathers, living the eccentric artist lifestyle, and riding out their mother's mental highs and lows. But losing their mother irrevocably breaks them, and Minnie wonders if she could lose everything: her family, her future, her first love . . . and maybe even her mind.

My heart is a kaleidoscope, and when we kiss it makes my world unravel . . .

Last summer, Gottie's life fell apart. Her beloved grandfather Grey died and Jason, the boy to whom she lost her heart wouldn't even hold her hand at the funeral. This summer, still reeling from twin heartbreaks, Gottie is lost and alone and burying herself in equations. Until, after five years absence, Thomas comes home: former boy next door. Former best friend. Former everything. And as life turns upside down again she starts to experience strange blips in time - back to last summer, back to what she should have seen then . . .

During one long, hazy summer, Gottie navigates grief, world-stopping kisses and rips in the space-time continuum, as she tries to reconcile her first heartbreak with her last.

The Square Root of Summer is an astounding and moving debut from Harriet Reuter Hapgood.