As The Doctor and Clara embark on a terrifying mission involving an alien conspiracy, Clara has to discover who the new Doctor is and if their friendship will survive.
Clara doesn't understand how The Doctor regenerated into someone older and is concerned about him. Madame Vastra determines that Clara is being judgmental because he no longer looks like the hot young thing he was before. Clara only ever had one pinup on her wall -- that of Marcus Aurelius. She demands Vastra does not presume to judge.
The Doctor is just as concerned about the frown lines he didn't create and his stern eyebrows as is Clara.
The Doctor and Clara meet up because of an Impossible Girl ad, but they are in trouble with the spontaneous combustion man!
They battle the bad guys while Clara tries to understand the new Doctor and while tries to become familiar with his new form.