Well, well, well, nothing slowed down in the second episode did it?
Just when the nerves had settled and the main storyline resolved everything seemed all right and at peace in the world until ... the plot twist of all plot twists.
The mysterious third Holmes brother turned out to be ... a sister!? Eurus ( "my parents loved silly names") had been right under our noses for the past two episodes. Smooth and how very ... Holmes-like.
And, er, also, surely she didn't really just shoot Dr Watson!?
We're already salivating at the thought of episode three next week.
Elsewhere, we were introduced to a brand-new villain, the sinister, squint-toothed Culverton Smith, who Sherlock described as the "living, breathing coagulation of human evil".
The serial killer's disarmingly cool disposition and velvet-smooth, slightly lispy accent definitely creeped fans out.
Moved by the trauma of the previous episode, we were introduced to a Sherlock strung-out on drugs, disoriented and hallucinating, lapsing into unhinged, gun-wielding rants.
People couldn't follow what on Earth was going on for most of the episode but, as always, the master plan pulled together at the end.
On to more serious matters, the stubble on the unshaven Sherlock drew a few admiring eyes.
Mrs Hudson, who kidnapped Sherlock and provided eye-stingingly funny sass throughout, won a lot of fans.
And, hearts were warmed and eyes moistened at the super emotional hug between Sherlock and John.
Hurry up next Sunday! So many questions ...