we may never know the truth ??
I haven't the faintest idea what this じまい is.
My best guess was that it's a contraction of でしまい (from で + しまう) to give わからずじまい = "end up not knowing". However, I have two problems with this theory: 1) かもしれない goes on the dictionary form of a verb, not the masu-stem; 2) I don't really understand how ず (which I'm assuming is negation) interacts with other grammar, but I see no place for で in the first place. I'm stumped.