In my opinion, John O'Callaghan's best track. Although Big Sky was a technical marvel, for me Mercury remains as JOC's magnum opus. Mercury has that "it" factor that's difficult to describe in words. You can tell based on the arrangement, clever manipulation of sounds, ambiance, and melody that JOC worked extremely hard on this track, more so than any other production he made. As one of his first releases, Mercury walks the fine line between the creativity of a young, aspiring, amateur producer and the expertise of an established professional - and that's precisely where trance sounds best.