One ordinary Tuesday, Katie finds herself catapulted into a parent's worst nightmare when a precautionary blood test reveals her five-year-old son Josh has leukaemia. The school run is diverted to the hospital emergency department, and she enters a parallel universe where chemo drips and hair loss are the norm, and even touching the supermarket trolley is a threat to Josh's life. With two more little boys and a husband with a spinal cord injury, Katie has to learn to balance family life with months of intensive hospital treatment for Josh. Her raw vulnerability is exposed as she finds a strength she didn't know she had - a strength fortified by moments of completely unexpected beauty and humour.

As survival mode kicks in, fuelled by a tidal wave of adrenalin, Katie is scooped up into an extraordinary healthcare system that ultimately saves Josh's life, leaving her blindsided with gratitude which she feels as a tangible thing: her gratitude cloak.