Der letzte Kampf(1923)

The industrialist's daughter has been kidnapped by the mad inventor Ravello, but Harry Peel stays hot on their trail with the help of his dog Greif. Behind a waterfall, he discovers the hidden gate to Ravello's castle, where the fiercest of battles now break out between the two and Harry finds himself confronted with a staircase that has been electrified and, once again, with the deadly robot.