In the early 1850s everyone knows that the Murray River has potential for river traffic. It takes months for drays to bring stores to isolated stations, and sheds packed with wool bales wait for transport to market. The South Australian government offers a cash reward for the captains of the first two steam-powered vessels to not only arrive at the Murray, but travel upstream to the junction with the Darling. Two men answer the call. The first is William Randell, from Gumeracha. William and his brothers build their fifty-five foot Mary Ann in an Adelaide Hills sawpit, then assemble it on the banks of the Murray, installing a small beam-type steam engine made by a local engineer of German descent. The second man to throw his hat into the ring is Captain Cadell, a sea captain of long experience and a budding entrepreneur with grandiose designs. With the help of wealthy investors, Cadell has his 105 foot Lady Augusta built in a Darling Harbour shipyard, with twin state-of-the-art horizontal steam engines, and accommodation for thirty. Cadell and Randell would both like to be remembered as the founders of Murray River navigation. Both are ambitious and highly skilled in their own way. This is the story of what happens when they pit their skills against each other, and against one of the mightiest rivers on earth.