Charlotte Lord, a widow in her early forties and owner of Manhattan's smartest modiste shop, is about to marry Guy Barton, a wealthy businessman. The marriage has the full approval of Charlotte's three daughters, Jane, Marilyn, and Leni, and their two friends, Lois and Mary Wilson. But Mexican divorces have been declared illegal, so Guy is still married to Sybil Barton, an unscrupulous gold-digger who left him 12 years earlier. She demands that Guy give her $250,000 for his freedom. The Lord girls plot with the Wilson girls and their older brother Steve, with whom Jane Lord is in love. They want to have Sybil declared incompetent so that Guy will have grounds for an American divorce. All of their schemes fail and the girls decide that the only thing that will divert Sybil from her extortion purpose is if she becomes involved with a man even richer than Guy. To this end they invent a fictitious Argentine, name him "Don Pablo" after a name they see on a cigar wrapper. They inveigle Steve Wilson to impersonate this South American millionaire who is to sweep Sybil off her feet. Later, a Buenos Aires millionaire named Don Pablo is greatly surprised when he reads in a newspaper that Guy Barton is suing his wife Sybil for divorce, and naming him co-respondent, and he decides to fly to New York and check this out.