Sherlock: 6 Reasons It Needs To End (And 4 Reasons It Should Come Back)

5. Hard To Keep Raising The Scale

Sherlock might have only had four seasons but each successive run has tried to top the last, resulting in it feeling like there is now nowhere to go but down.

Let's look at the finales, for example. Season one's saw the introduction of Moriarty and the tense cliffhanger of Sherlock and Jim caught in a Mexican stand-off. The second saw Moriarty kill himself and Sherlock return from the grave. The third threw in a massive twist about one of the core characters and then ended on the infamous "Miss Me?" tease.

The fourth, meanwhile, went bigger than ever. The Final Problem raised the game on a personal level higher than ever before, seeing as Sherlock was revealed to have an evil sister who put the characters through some traumatic tests.

How could season five possibly go bigger than that?