A twisted plot demonstrates that the ""stuff of dreams"" can result in murder. Camilo Canegato, a shy artist, creates an imaginary dream girl he calls Rosa and relishes the new substance this gives to his life, especially in relation to the other enants and the landlady of the boardinghouse he has inhabited for twelve eventless years. As their curiosity and interest reaches its zenith, Camilo thinks out a plausible frustrated ending to the imaginary affair and is soaking up sympathy when a mysterious girl arrives and is mistaken for ""Rosa"". To his consternation she plays along with the error, finally trapping him into marriage and goading him into violent retaliation. Interesting in its intra-boardinghouse relationships. (Cheers for the discreet doorman!)