LEMNISCATA is the symbol for infinity. It's a concept that gains a new meaning for the Lisbon correspondent for The New York Times, who spends two electrifying weeks in Brazil during the summertime pre-Carnival season, where her life is in constant danger. At the same time that she must unravel the riddles anonymously received by e-mail, she is under the scrutiny of a threatening and skilled Egyptian assassin, famous for his ability to remain undetected by his victims.Lorena