Based on the incredible true story of D'Arcy Wentworth and his horrific journey to Australia from England via the Second Fleet, Mystery on the High Seas takes us on a rollicking journey through the eyes of Molly O'Hanlon, a fictional Irish girl.

When Molly's father is accused of a crime he didn't commit, Molly and her ma join him on the journey to Australia. They do this aboard a ship known as the Hell Ship Neptune, due to its appalling conditions and evil captain, Donald Trail. Molly is drawn into D'Arcy's world and, in doing so, is also drawn into a world of duels at ten paces, betrayal, theft and even attempted murder!

Interweaving true historical events with creative license, Mystery on the High Seas has real-life characters such as D'Arcy, Captains Gilbert and Trail, and Lucky Gem, as well as historically correct dates, such as the time the Neptune left England, docked in Cape Town among other things.