Final answer:
The answer about why Madam Lockton has a party after Curzon's capture is 'd) Not mentioned' as the provided text does not give information on her motives.
Step-by-step explanation:
The question revolves around the character Madam Lockton from a narrative, possibly a work of fiction, and her motives for having a party. Based on the provided text, which does not mention Madam Lockton directly, it is impossible to draw a precise conclusion about why she has a party after Curzon's capture. The text focuses on a different character, Louisa, and her feelings of relief and security in her domain. Therefore, without additional context from the work that this question is derived from, the answer would be d) Not mentioned.