Dragnet Night.

A sailor, who meets a lovely music hall singer during a police raid, falls in love. In a contest at a fair, he defeats a former boxing champ. The ex-champ trains the sailor to become a boxer. After he wins the French championship, the sailor is swayed by easy money and a sultry coquette. The singer goes on a singing tour, and the sailor falls into decadence. He enters the European championship spiritually empty and in bad condition.