The palace is the vision of the idealistic Gabriele del Campo, a young stonemason's apprentice tossed into prison for supporting Garibaldi's revolutionary unification of Italy. A poor peasant, he has fallen in love at first sight with the rich and beautiful noblewoman Donna Donatella. He yearns to be pulled out of poverty, and dreams of winning Donatella's heart and building a palace worthy of his love.

As del Campo languishes in prison, he takes the first steps toward his dream. His cellmate Colonel Giovanni Vitelli, a nobleman, educates him in the customs of the gentry; meanwhile, in his mind, elaborate plans for the palace's construction are already taking shape.

Then comes the fateful chance in which he had always believed. Twice escaping execution, del Campo emerges from prison to find riches as a fearless gambler in the corrupt underworld of Venice. Winning a large estate in Castello at a sinister high-stakes gambling house, Gabriele begins to build the palace of his dreams. At last he might win Donna Donatella's love.