There's no 'mystery' (to/as to/about) why we're here. = It's no 'mystery' why we're here. [=we know why we are here]
His success is something of a 'mystery'. = His success is a bit of a 'mystery'.
We'll reveal the identity of today's 'mystery' guest after these commercials.
(..) ♪ The autotrophs began to drool, Neanderthals developed tools ♪ ♪ We built the Wall ♪ ♪ ♪ ♪ Math, Science, History, unraveling the mystery ♪ ♪ That all started with a big bang ♪ ♪ ♪ Original Air Date on September , == sync, corrected by == (..)2011 TvShow: The Big Bang Theory Title: The Skank Reflex Analysis Season: 5 Episode 1