Sherlock: Every Episode Ranked Worst To Best

A Scandal in Belgravia is a key entry in the Sherlock canon for two reasons: we are introduced to the fan-favourite Irene Adler, and Sherlock is finally pushed out of his comfort zone. This is a story that blends a more ambitious adventure where national security is at stake and the shadow of Moriarty looms large, with a very funny romance between Sherlock, John and Irene.

Benedict Cumberbatch and Martin Freeman are in their element here, and Lara Pulver is having a ball as Irene Adler. We get to see Sherlock and John at their best, in equal parts amusing, affectionate and cheeky towards each other.

With all the hard work of establishing the contemporary detective and his partner out of the way, A Scandal in Belgravia is ludicrously enjoyable, and a welcome respite before we see everyone tested by Moriarty's dastardly schemes finally coming to fruition.

It is fascinating to watch Sherlock unaware of how to react to someone like Irene Adler, especially before he is softened by the likes of Mary and Molly. The episode works so well because Lara Pulver's performance makes the beloved character seem flawed and vulnerable, whilst genuinely feeling like someone who could outwit Sherlock Holmes.