A perigosto stick was an object which looked like a thin, silver probe with a tiny sphere on top. (PROSE: Love and War) Students at the Time Lord Academy used them to play games of four-dimensional juggling. (PROSE: Seeing I) The Doctor also claimed that it was a musical instrument. (PROSE: Deadly Reunion, AUDIO: Voyage to Venus) The First Doctor and his friend Ruath once electrified Cardinal Borusa's perigosto stick. (PROSE: Goth Opera)