Angus MacKay later played the Headmaster in "Mawdryn Undead".

Entity and relation annotations:
id: 0
type: entity
value: text: Angus MacKay
labels: <Person>
id: 1
type: entity
value: text: "Mawdryn Undead"
labels: <Work_of_art>
id: 2
type: entity
value: text: the Headmaster
labels: <Person>
type: relation
to_id: 1
labels: Person:performs:Work_of_art
from_id: 0
type: relation
to_id: 1
labels: Person:is_character_in:Work_of_art
from_id: 2