For a time prior to the arrival of the Doctor's TARDIS, Cassandra had had nightmares of the future. A mean-spirited and vindictive sort, she nevertheless warned Priam and those associated with her that doom would come to Troy, the people of which had long failed to take her seriously. When Vicki (later called Cressida) emerged from the TARDIS, which the Trojans had taken to the city, Cassandra immediately accused her of practising witchcraft. She warned of the Trojan Horse (a plan put into action by the First Doctor, borrowing the idea from Homer), but to no avail.
She was resurrected in the City of the Saved as a young woman. In AF 291, while on the Tube, Cassandra prophesied in painstaking detail the imminent Civil War. (PROSE: Of the City of the Saved... Prologue)