This episode attracted 9.8 million viewers on initial broadcast.

Leela: We might have been killed!
The Doctor: It's ten feet, from whisker to tail.
Leela: We should have taken weapons!
The Doctor: What kind of weapons? You need a harpoon to stop that brute.
Leela: Shall we tell the blue guards?
The Doctor: They'd only call a sanitary inspector.

Casey: Aren't you coming, Mr. Jago?
Henry Gordon Jago: Some paperwork commands my presence yet a while, but I shall doubtless descry those lugubrious liniments at the crepuscular hour.
Casey: Eh?
Henry Gordon Jago: See you in the morning!

Professor Litefoot: Upon my soul. I'm sure we shouldn't be discussing such things in front of the fair sex. Forgive me, ma'am.
Leela: What for?
Professor Litefoot: For being so indelicate in the presence of a refined lady!
Leela: Does he mean me?
The Doctor: I don't think so.

Professor Litefoot: Upon my soul!
The Doctor: (about Leela) Savage. Found floating down the Amazon in a hat box.
Professor Litefoot: A hat box?!?

Leela: Why are you making fire in your mouth?
Professor Litefoot: What? Upon my soul, hasn't the girl seen a pipe before?
The Doctor: There's no tobacco where Leela came from.
Professor Litefoot: Sounds healthy but exceedingly dull.

When the Doctor tells Professor Litefoot that there is no tobacco where Leela comes from, he responds "Sounds healthy but exceedingly dull." During the late 19th Century and well into the 20th Century, it was believed that smoking was beneficial to one's health.

This episode introduces the concept of Time Agents, which will later be expanded upon in the new series in the episode "The Empty Child."