Rex (The Eternal Mystery)

From Tardis Wiki, the free Doctor Who reference

Rex was a captain of the palace guard on Krontep who was assigned to the Temple of Yrcanos.

One day, he caught a hooded figure in the temple and chastised them for being there, before discovering that it was in fact the long-disappeared warrior-queen Peri Brown. He told Peri what her disappearance did to the planet and that he wanted to travel the universe like her. Revealing that she had returned to travelling in the TARDIS with the Sixth Doctor, explaining her disappearance, she invited him to join her and the Doctor. (WC: The Eternal Mystery)