 Marco De Vally, a young decayed aristocrat and poet, has been found dead in his room. Suicide or murder ? Police inspector Fabio Russo starts his investigations from a short poem the victim was writing: IL PINO AZZURRO (The blue pine tree), which contains some obscure hints at famous and important people. Other alarming clues are given by Luca Porri, the victim s disquieting and somehow mad psychoanalyst, and Sarah Pierce, Marco s former lover, who put P.I. on the track of a colossal traffic in arms and drug. Eventually, the scandal breaks out: several politicians and financiers are arrested and charged with trafficking in arms and drug and with Marco s murder, which they confess even if the actual killer can t be found. When P.I. Russo hits on Marco s farewell letter announcing his suicide for Sarah s unrequited love, he throws it away.