As the wife of retired ship's doctor Dr Henry Parker, Evelyn is living out her twilight years aboard the Golden Sunset.
Every night she dresses for dinner - gown, tiara, runners - and regales her fellow passengers with stories of a glamorous life travelling the world in luxury as well as showing off her superior knowledge of everything from ships' customs to biographical details of her heroine, Florence Nightingale. The crew treat her with deference. And forbearance.
But when Henry goes missing, Evelyn sets off to search every part of the grand ocean liner to find him, casino, nightclub and off-limits areas included. Misadventures are had, new friends are made, scandalous behaviour noted - all news to Evelyn.
If only she could remember the events of the night before as clearly as she can recall the first time she met Henry on a passage from England to Australia in 1953 and fell in love, abandoning her dreams to become a midwife to be a wife instead - and the long-ago painful events that left Evelyn all at sea.
Why is it so hard to remember some things and so hard to forget others? And where is Henry?
The Last Voyage of Mrs Henry Parker is a love letter to the memories we make over the course of a lifetime, and how the heart remembers what matters, even when the mind has long forgotten.