Reviewed by Phil Boothman.

Over the past weeks it has become clear that Elementary is at its best when it provides a truly nasty or complex villain for Holmes to face down, like the Balloon Man or Sebastian Moran. When the show falls down is when it pits Holmes, the master investigator, against crimes of passion or clumsy cover-ups: fortunately, “The Deductionist” falls into the former category, and comes up with a truly horrible piece of work.

The meat of the episode concerns the hunt for one Martin Ennis, a convicted serial killer who escapes in the early minutes of the episode in the most brutal fashion possible, using the opportunity of donating a kidney to his ailing sister along with a scalpel and his own violent tendencies to make his exit. As Holmes and Watson are called in, they see the word ‘SHEDIR’ scrawled on the wall in blood, and Holmes immediately recognises it as a name for the star Cassiopeia.

Shortly after this we meet Katherine Drummond, the profiler who helped put Ennis away originally, who wrote a book containing an unfounded theory that Ennis was sexually abused by his parents. She also happens to be an old flame of Holmes’, who went on to write an article about him called ‘The Deductionist’ which predicted many of his later struggles, particularly with addiction. Needless to say, Holmes isn’t exactly pleased to see Drummond, and his animosity towards her is evident throughout the episode.

Holmes takes a quick break from being cold towards Drummond to disprove the idea that ‘Shedir’ means anything: Ennis’ victims appeared to follow a pattern based on the star Cassiopeia, but Holmes correctly dismisses it as a red herring.

Meanwhile, Ennis attacks more people in a convenience store and gets a young woman who fits the profile of his previous victims to take a photo of him, leaving Holmes to deduce that he is attempting to convey a message, but he admits he is unsure of what the message is. However, after Ennis calls the police station and addresses Drummond directly, Holmes works out that Ennis is targeting Drummond for supposedly ‘solving’ him: Ennis tells Holmes it is because Drummond’s allegations destroyed his family, her book leading to his father’s suicide and his mother’s subsequent death.

After a tip that Ennis broke into his sister’s house, Holmes and Watson find a large number of food products which would damage kidney functions, correctly deducing that Ennis’ sister was in on the act, deliberately poisoning herself so that Ennis could escape while he was supposed to be donating his kidney. However, before they can reach her, she attacks Drummond with a pair of scissors, severely injuring her, and is arrested soon afterwards.

Ennis calls Gregson again soon after, and Holmes works out where he is hiding based on two of the radio stations Ennis dialled past while he was calling the police. He confronts Ennis about the effect Drummond’s words have had on both of them, and Holmes admits his fear that she is correct about his life only possibly ending in ‘self-annihilation’. He offers Ennis a choice: he can go for his gun and violate Drummond’s profile of him which states he is a coward, in which case Holmes will attack him in response; or he can go for the handcuffs, going quietly but confirming the profile. Naturally, he goes for the gun, and Holmes beats him down with a ‘single stick’, which he was seen practising with earlier.

This confrontation was one of the best we’ve seen in the entire season, almost reaching the heights of Holmes’ confrontation with Moran in “M”. It was tense and sinister, but also revealing about Holmes and his acknowledgement of his inadequacies: following up his almost preternatural deduction about Ennis’ whereabouts with a discussion regarding his fears of self-destruction provided a pleasing contrast between the ‘superhuman’ and regular human elements of Sherlock. Similarly, the tension between Holmes and Gregson continues to simmer along, as Gregson clearly wasn’t happy with Holmes’ decision to confront Ennis alone.

The subplot was a little on the flimsy side, but allowed Watson to stretch her own investigative muscles: she returns to her apartment to check on some noise complaints about her sub-letters, only to find that she is being evicted for allowing her sub-letter to shoot a pornographic movie in the apartment. She confronts her sub-letter, who apologises, stating that he needed quick money to fund his failing documentary filmmaking career. However, upon watching the movie after Holmes pointed out the many continuity errors which make it ‘basically unwatchable’, Watson notices black electrical tape on the radiator, placed there by her landlord. She confronts him about this, stating that it confirms that he was on the premises when the movie was being shot and that he allowed an unlicensed production on private property. She also accuses him of attempting to evict her so he could charge market price for the rent, and forces him not only to pay to have her stuff moved into storage while she finds a new apartment, but also to buy her a new couch, considering what happened to it in the movie.

It was nice to see Watson become a little more independent in her burgeoning investigative career, but her subplot seemed to be massively at odds with the much darker, more sinister main plot. Fortunately, it wasn’t given a vast amount of screen-time, so it didn’t detract from the overall tone of the episode too much.

Verdict: 7/10

A pleasingly sinister villain and some interesting revelations about Holmes’ own mental state help this episode trundle along nicely, and I am beginning to see a loose arc regarding Holmes letting down the people he trusts. However, the subplot drags the episode down a little, meaning it doesn’t quite hit the heady heights it could have done so easily.