The Zygon Inversion Trivia Quiz

Answer: Toothpaste

Clara is in sort of a dream state, as she is inside the Zygon pod. She goes into the bathroom and picks up a tube of toothpaste - we know because it says "This is toothpaste." Possibly the most generic prop ever.

Clara has woken up, realized that she is controlled by a Zygon - but then determines that she can also control Bonnie. What follows is a battle of wills between Clara and Bonnie. A bravura performance by Jenna Coleman.

Answer: Union Jack (UK Flag)

The Doctor and Osgood managed to narrowly escape the missile heading towards their plane and landed on a beach. Taking a page from James Bond ("The Spy Who Loved Me"), the Doctor's parachute had a Union Jack on it. When Osgood asked why, the Doctor explained "camouflage."

This was the first time the Doctor has used a parachute in the history of the television series, although he has used them in other media such as books.

Answer: Dr John Disco

Continuing on a joke from "The Zygon Imvasion", the Doctor called himself John Disco. This is just one of many aliases the Doctor has used over the years. John Smith is the Doctor's most frequent alias.

Answer: Zygella

The Doctor calls Bonnie Zygella, a name which she dislikes quite a lot. Balmy is a British slang term for crazy. Gonzo is an American slang term meaning crazy or unusual.

At the end of the episode, it was revealed that Bonnie/Zygella had shed her Clara persona and become a second Osgood.

Answer: Basil

The Doctor says his first name is Basil, but remember the first rule: "The Doctor lies." Osgood says that her first name is Petronella, at which point the Doctor goes back to calling her Osgood.

Basil, if by chance the Doctor is telling the truth, has its roots in Greek. It is the English variant of the Greek name Vassilios, meaning king. Basilica means "the chamber of the king". Basil is a common name in Eastern Europe. It is also the name of a common herb.

Petronella is a name with Latin and Italian roots, coming from the first century Saint Petronilla. Petronella is the Germanic/Scandinavian version of the name. Notable Petronellas include two British actresses (both Barker), several Dutch athletes (Burgerhof, van Randwijk and van Vliet) and British author Petronella Wyatt.

Answer: five rounds rapid

Veteran watchers of "Doctor Who" cheered when Jemma Redgrave delivered the line "Five rounds rapid" which was a tribute to the classic Brigadier line "Chap with wings there, five rounds rapid" from "The Daemons" (June 1971).

Kate was in quite a dilemma at the end of "The Zygon Invasion". The sheriff who had been escorting her around Truth or Consequences turned out to be a Zygon. Luckily for Ms Stewart, she was armed and blew several holes in the Zygon.

This was Jemma Redgrave's sixth appearance as Kate Stewart on "Doctor Who". She first appeared in "The Power of Three" (2012), was in the 50th anniversary special "The Day of the Doctor" (2013), last season's finale "Death in Heaven" (2014) and has showed up three times this season. Redgrave has been acting in both films and television since 1988. She is the daughter of Corin Redgrave, the brother of Lynn and Vanessa.

Answer: Earth destroyed by a cascade of nuclear warheads

According to the Doctor, the box that Kate Stewart had would either release nerve gas that would kill the Zygons or set off the nuclear warhead buried under the Tower of London. The box that Bonnie had would either unmask the Zygons for one hour (which Bonnie hoped would cause a war) or cause the Zygons to permanently become human.

The nuclear weapon underneath the Tower of London was first referenced in "The Day of the Doctor" (2013). The Z-67 nerve gas was specifically referred to as "Sullivan's gas", a reference to Doctor Harry Sullivan, a companion of the Fourth Doctor. It was suggested that Harry had engaged in secret research after leaving UNIT.

The wrong option - earth destroyed by a cascade of nuclear warheads - would be the Osterhagen Key, which was described in "Journey's End" (July 2008).

Answer: Neither

The Doctor manages to convince Bonnie that she should not press either button. He does imply that it took fifteen times before she agreed to stop. The Doctor kept resetting the memory device in the Black Vault until he got the outcome he wanted.

Peter Capaldi gives an impassioned speech about the horrors of war, about the things the Doctor has done and seen. "I've done worse things than you could imagine. When I close my eyes, I hear more screams than anyone could be able to count" he states, and says that he has made it his mission that nobody else ever faces the same horrors.

Answer: I'm a very big fan

The Doctor did say that Petronella was a credit to her species (whatever that may be), but his last line was "I'm a very big fan."

"Which one are you?" was a question that the Doctor asked Osgood repeatedly throughout both episodes, and a question that Osgood refused to answer.

When Osgood asks what TARDIS means, after being somewhat astounded that the ultimate fan girl didn't know, the Doctor said "Totally and Radically Driving in Space."
For the record, it stands for "Time and Relative Dimensions in Space" - at least according to Susan Foreman, and she should know.

Answer: Steven Moffat

Steven Moffat was listed as the co-author. Moffat has been the show runner of "Doctor Who" since the start of 2010. Moffat is the author of the most "Doctor Who" scripts in the history of the show, with 40, including many season openers and finales. His first script for the new series was "The Empty Child/The Doctor Dances" (2015). He has won numerous HUGO and BAFTA awards for his writing.

Daniel Nettheim was the director of both "The Zygon Invasion" and "Zygon Inversion". He is a native of Sydney, Australia and most of his work has been done in Australia television, although he does have several episodes of "Glee" on his resume. Nettheim also directed the Willem Defoe film "The Hunter" (2010).

Nicholas Asbury played Etoine, the poor Zygon who was outed by Bonnie near the beginning of the episode. Asbury has been working in British television since 2002. One of his bigger credits was as Winston Churchill in the mini-series "37 Days" (2014).

Ray Holman was the costume designer for the episode, as well as the rest of Series 9. Holman was also costume designer for the 2010 season ("Bowties are cool.") as well as giving Sally Sparrow her style in "Blink" (2007).