Act I. Lisbon. The Royal Council Chamber of Portugal. Nothing has been
heard of the ship of Bartholomew Diaz, the explorer. Among his officers was _Vasco da Gama_, the affianced of _Inez_, daughter of the powerful nobleman, _Don Diego_. _Vasco_ is supposed to have been lost with the ship and her father now wishes _Inez_ to pledge her hand to _Don Pedro_, head of the Royal Council of Portugal.
During a session of the Council, it is announced that the King wishes to send an expedition to search for Diaz, but one of the councillors, _Don Alvar_, informs the meeting that an officer and two captives, the only survivors from the wreck of Diaz's vessel have arrived. The officer is brought in. He is _Vasco da Gama_, whom all have believed to be dead. Nothing daunted by the perils he has been through, he has formed a new plan to discover the new land that, he believes, lies beyond Africa. In proof of his conviction that such a land exists, he brings in the captives, _Selika_ and _Nelusko_, natives, apparently, of a country still unknown to Europe. _Vasco_ then retires to give the Council opportunity to discuss his enterprise.
In his absence _Don Pedro_, who desires to win _Inez_ for himself, and to head a voyage of discovery, surreptitiously gains possession of an important chart from among _Vasco's_ papers. He then persuades the _Grand Inquisitor_ and the Council that the young navigator's plans are futile. Through his persuasion they are rejected. _Vasco_, who has again come before the meeting, when informed that his proposal has been set aside, insults the Council by charging it with ignorance and bias. _Don Pedro_, utilizing the opportunity to get him out of the way, has him seized and thrown into prison.