From TARDIS Index File, the free Doctor Who reference.

For other individuals named Briggs, see Briggs (disambiguation).

Samantha Briggs was the sister of Brian Briggs. When he disappeared while taking a Chameleon Tours trip to Rome, she went to Gatwick Airport to investigate, and teamed up with the Doctor to find the other missing persons and with him, defeat the Chameleons. (DW: The Faceless Ones)

Behind the Scenes

Samantha was originally intended to become the Doctor's full-time companion at the end of The Faceless Ones but Pauline Collins turned down the offer to become a series regular. In her absence, Victoria Waterfield from the following story The Evil of the Daleks was chosen to be the next companion. (The production crew had also considered Mollie Dawson as a companion.) Pauline Collins would return to Doctor Who for Tooth and Claw, in which she played Queen Victoria.