From their very first meeting, the young Bertha Ringer is enchanted by Carl Benz's ideas and dreams for motorised locomotion. She fights a hard battle with her parents to marry him, for they fear that Bertha will be unhappy with an indebted engineer without the bourgeois security to which she is accustomed. In fact, Bertha will have ample opportunity to demonstrate confidence and stamina in her marriage, for Carl's invention requires not only technical know-how, but also a great deal of time, laborious investors and even more persuasion. Nevertheless, after hard years, Carl Benz succeeds in developing his combustion engine into a horseless carriage. When nobody wants it, Carl is ready to give up. Spontaneously, Bertha sets off on a pioneering journey with her sons to prove the car's roadworthiness.