The puzzle you're working on is based on a one-time pad cipher, and it appears to involve subtraction of values based on a key (here labeled "Book, B") and the given code (labeled "Code, C"). Here’s a step-by-step breakdown of how we can approach solving it:

1. Cipher Letters (C): The given letters "IEHIKWPWDSNXFJWNXIW" represent the cipher text.

2. Book (B): This section seems to be for inputting a key from a known book or reference, but for now, it’s blank. If the puzzle provides a key (usually numerical), we subtract these values from the corresponding cipher letters' numeric values.

3. Subtraction (C - B): This formula tells us to subtract the book value (B) from the cipher text's corresponding values to decode the original message. The alphabet is indexed from A = 0 to Z = 25.

The approach for this kind of cipher is as follows:

• Convert each letter from the cipher text into its corresponding numeric value (A = 0, B = 1, ..., Z = 25).
• Subtract the corresponding number from the book code.
• Convert the resulting numbers back to letters.

To proceed, I would need the key or book values (B). Without this, it's impossible to fully decode the message.

Do you have any additional clues or instructions that provide the key? Alternatively, we can start by converting the cipher letters into numbers in preparation.

Would you like me to help convert the cipher text to numeric values or guide you through another step?

Relative questions:

1. Do you have access to a key or reference for the "Book"?
2. Is there any additional clue provided in the puzzle instructions that could help solve the cipher?
3. Have you worked with similar cipher techniques before (e.g., Vigenère cipher)?
4. Would you like a step-by-step guide on how to solve a one-time pad cipher manually?
5. Is there a specific part of the puzzle you’d like me to explain further?

Tip: In a one-time pad cipher, the key (B) must be the same length as the message. Always check for clues in the puzzle text that may hint at the key.