When we think of war, we often picture the biggest danger being the guns, bombs, and bullets. But until the early 20th century, disease was actually the greatest killer on the battlefield. In several campaigns, illness claimed twice as many lives as enemy fire.

During the Second World War, Major Henry Shannon played a critical role in the fight against this hidden enemy. Through innovative inventions and educational posters, he worked to protect Australian troops from the devastating impacts of disease.

In this episode, Major Shannon's granddaughter, Gabby Walters, explores his ground-breaking work and the legacy he left on the Australian Army Medical Corps.