Tyra Nordbo is a character from the Man-Kzin War series of books, introduced in the stories collected in Inconstant Star. She was a native of Wunderland, daughter of Landholder (a noble) Peter Nordbo. During the First Man-Kzin War, Peter was pressed into service for the Kzin following their occupation of the world. At the height of the occupation, he discovered a source of bizarre radiation on a world many lightyears away, and was taken to investigate by the scientifically minded Kzin who oversaw him.
During the flight, forces under Buford Early and Ulf Reichstein Markham liberated Wunderland, and Peter was convicted of collaboration and stripped of all of his possessions. In order to secure his release and clear his name, Tyra secured the help of Robert Saxtorph and his ship to investigate, following the death of Markham, who had forbidden them to go using his position as Interworld Space Commissioner. Before leaving, Tyra had supported herself as a journalist and married Jonah Matthieson, one of Early's soldiers, having had an adventure exploring the Jotuun Mountain Range beforehand.
They found that Peter had discovered a remnant of the Tnuctipun, a black hole powered hyperdrive that could also be used as a powerful Hawking radiation beam weapon. Peter had freed himself from the Kzinti and was reunited with Tyra, and after the weapon was destroyed by the Kzin, returned to Wunderland to free his name.