Watch Brett in action and you're glad he hid his personal charm as well as he did (from all accounts, he was a lovable and loving man). His Holmes prefers to leap over chairs rather than walk around them. The force he brings to the part is dark, edgy, sometimes reckless. Brett was clinically bipolar, and while it would be an insult to his talent to assume that the illness helped make his Holmes so mercurial and unpredictable, there's no doubt that, as Conan Doyle describes him, the great detective endures dark lows and manic highs. Thus the c0caine and the smoking (Brett had a three-pack-a-day habit he found devious ways to indulge during the filming).
Unlike the cold, analytical Holmes embodied by Basil Rathbone, Brett's is passionately, warmly alive. The warmth is doubtlessly his essential humanity shining through the neurotic trappings. He's playing a man who is notoriously closed, yet you can see him feeding on his own intelligence when the essence of a problem possesses him; it's the hectic fever in his eyes and the play of nerves and muscles in his face, especially in the odd, twitching half-smiles that are among his rare flashes of civility. To understand the wildness he brings to the role, think of a less murderous Mr. Hyde. His Holmes storms around the flat at 221b Baker Street like a caged tiger; you can almost see the walls shaking. His "filing system" is a masterpiece of mad-genius chaos. He flings his papers about in a fury, leaving the mess for the steadfast, often exasperated housekeeper Mrs. Hudson (Rosalie Williams) to clean up.
Brett's random, often seemingly involuntary gambits make his quiet moments all the more moving. A talented singer who was told early in his career that he could be an opera tenor if he dedicated himself to it, he has the power to send his voice to the depths of the balcony with ease, to bully and intimidate at the top of his bent, and then come beautifully down to earth as he does at the end of the episode titled "The Second Stain." Having been congratulated in uncharacteristically heartfelt terms by Inspector Lestrade of Scotland Yard (Colin Jeavons) after a particularly miraculous feat of detective work (he has just saved England, in effect), he drops in the space of a heartbeat from a ringing, typically imperious acknowledgment of the compliment to a humbled, barely audible "Thank you."
It's hard to imagine any actor surpassing or even matching what Brett accomplished in these 41 episodes. I haven't seen the Holmes played by the Russian actor, Vasili Livanov, whose work earned him an OBE, but my guess is his was a more contained, less extreme portrayal, one less likely to offend the Queen's sensibilities. Again, it seems a crime that Brett never received the formal recognition he deserved.
It's worth repeating the invaluable contribution of Burke and Hardwicke in bringing Dr. Watson to life as Doyle intended him: a man whose skills as a physician, pugilist, and documentarian are indispensable to his difficult, fascinating, and ultimately beloved friend. Brett considers that relationship one of the glories of the series: "To me, the Sherlock Holmes stories are about a great friendship. Without Watson, Holmes might well have burnt out on c0caine long ago. I hope the series shows how important friendship is."