The BBC's Sherlock had a strong start, but it peaked very early and that marked the beginning of the show's downfall, although it wasn't the cause.

BBC's Sherlock had a perfect replacement with the debut of Elementary, another fantastic adaptation of the Holmes stories.

Though the U.K. has already gotten the chance to see the new episodes of the acclaimed and obsessed-over BBC show Sherlock, the episodes start to hit American TV Sunday night. So if you're going to ...