To be beyond the pale means to be completely unacceptable or inappropriate, and in this sentence the speaker is saying that it is unacceptable for the other person to try and blackmail them.
Context: It's completely unacceptable and inappropriate that you believe you can blackmail me like this.
Hypothesis: It's beyond the pale that you believe you can blackmail me like this.

Is the hypothesis incorrect? (Yes, no, or unknown)?