Max Wrottesley is incorrectly credited as Maz Wrottesley in the opening credits.
Val Todd receives a phone call from Lane of SCDP on the East Coast. On the show Mad Men, set in 1966 New York, Lane Pryce is a partner in the SCDP advertising agency.
Geoffrey Streatfeild is incorrectly credited as Geoffrey Streatfield in the opening credits.
In this episode the doctor discusses digitalis and mentions the plant deadly nightshade. However, digitalis comes from the foxglove plant, not from deadly nightshade, which is the source of belladonna, known medically as atropine.