sentences:  Tancred angrily arrives, in disguise as a footman, to defeat the young impostor, not knowing that it is his sister.He does not reveal himself because of the gypsies, but he hopes that they will kill his rival, whom they believe is Tancred.When the gypsies arrive, Boleslas challenges Falka to a duel denouncing "Tancred" for breaking his promise to marry Edwige.