The grandness and epic scope of HBO's Rome ultimately became its undoing. It was a ratings hit for the premium cable channel but it was also a co-production with the BBC and when the two year production contract was up, so was the BBC's end of the money chain – leaving HBO with the lot of the notoriously expensive and expansive bill. Knowing that they were only get to tell their tale in two seasons, the writers and producers had the show jump ahead many years in Season 2, soaring over the rest of the story they wanted to initially tell and leaping ahead to the end of the saga. So what was really missing from this series might not have actually been an extra season, but all the potential seasons they skipped over.
Journeyman completed its initial thirteen-episode order but when the writers' strike hit, NBC declined to extend the show and that was that. Only a modicum of closure was given in that thirteenth episode, with plenty of unanswered questions about what was happening to Dan that unfortunately were never answered. But wouldn't it have been great if they had?