I hadn't a clue what he was saying. What didn't I want to know?

If he'd meant that I didn't want to know what was in the envelope, he would have been correct. Between the fleshy feel to the contents and his sinister emphasis on the word finger, I was all too sure that there was a severed digit, stolen from a human hand inside.

But who did that finger belong to, and why would that address be written on the envelope?