Avsnitt 2

After a particularly nasty Paris thunderstorm, Paul, Paulette and Claude build a mouse raft and are accidentally carried off by the swirling waters of a gutter into the sewers of Paris. Claude uses his book knowledge to fashion several close escapes from three rats who are trying to harm them . Anatole, Gaston and Doucette work on a plan to stop the raft from winding up in the Seine and they are helped by another sewer rat named Elmore, who has been trying to save the kids himself. In a cooperative effort all around, the kids are snared into safety in the nick of time.