Rumors persist it's simply Thousand Island dressing, perhaps with some pickle relish thrown in. Others cry foul -- surely it's more than that! This secret recipe is so secret, it somehow got misplaced (as in lost) sometime in the 1980s. It was the restaurant chain's own fault. McDonald's wanted to cut costs, and created a cheaper special sauce. (Did customers even notice?) During the switch, the original recipe was lost, but no one knew because they weren't using it anymore. Years later, a former executive returned to the company, and wanted to bring back the original sauce. That's when employees realized the recipe was missing. Fortuitously, the executive knew who had produced the sauce 36 years prior, and contacted the company, which still had the recipe in its records. The original secret special sauce was back [sources: DailyFinance, Watson].