A Philadelphia nightclub offers Louis a higher salary, $500 per week. He leaves Boston and takes up temporary residence at the Philadelphia Zoo. The zookeeper promises that because Louis is only a guest, he will not be pinioned (have a wing tip cut off to prevent escape) like all the other swans at the zoo. One stormy night, Serena, blown off course, falls into the Zoo's Bird Lake. Louis serenades her by playing "Beautiful Dreamer" on his trumpet, and she falls in love with him, impressed by his song and the numerous possessions hanging around his neck. When the zookeepers spot Serena, they try to clip her wings, and Louis attacks them. He convinces the Head Man to postpone the operation for a short while and sends a telegram to Sam, asking for help. Sam goes to Philadelphia and strikes a deal with the Head Man: in every clutch of cygnets, there is always one that needs special care, just as Louis did in his own family. If the Head Man will let Louis and Serena go free, they will donate one of their cygnets to the zoo every year.