The Dragon Valley is flooded. A power plant is to be built nearby, so a river has been diverted. Sir Cedric brings Fumé a letter from Paris. An advertising agency wants to hire Fumé for a commercial! When the commercial is shot, there is a dispute. Fumé is supposed to be misused as an advertising figure for a liquor advertisement. A ray of fire escapes him and cameras and decorations burn. Despite the failure, however, father and son remain as tourists in Paris. During a walk they witness a house fire. Three people are trapped. The fire department is powerless. Grisu and Fumé manage to save the couple and their child. And yet another adventure awaits the two heroes in Paris. They run into a dangerous gang of burglars who are after the gold treasure in the National Bank's vault. The gang is disarmed by Fumé and Grisu and handed over to the police. Afterwards, father and son return to Drachental.