The Sarah Jane Adventures: The Empty Planet

Rani and Clyde wake up to find that all electrical appliances, including Mr. Smith, have stopped working and that they seem to be the only people in the city, which is completely deserted. They meet a young boy called Gavin but he is evasive and Clyde wonders if he is all he seems. After Rani has explained that she has met aliens, Gavin runs off and, going after him, Rani and Clyde find themselves pursued by two huge robots.