It is an uncomfortabel time for both.
Shortly after leaving Holmes Alfredo goes missing.
Holmes' once partner in addiction Oscar has taken Alfredo to make Holmes find his sister who supposedly has gone missing also.
I turns out to be a ploy by Oscar to once again drag Holmes down to his level and return him to addiction. Olivia, Oscar's sister, is already dead from an overdose, which Oscar already knows.
Holmes is forced to revisit his old rehab center and a crack house, dragging him closer to his past.
The episode was interesting in a very dark way, and although the ending suggests Holmes gave in to the Siren call of heron, I have my doubts that that is what happened. Cliff hanger for sure.
Canonically there were a few good observations and readings of clues, and the dark nature of addiction made for an interesting story.
We do not know the struggle the Canonical Holmes went through, if any, for his dependence on cocain. The inclusion of his addiction will always be an interesting part of the Canon and we will never know for sure why it became part of Sherlock Holmes back story. Millers Holmes is portraying the addiction as a defining part of Holmes personality, and a much more controling influence than is Canonically suggested (which should make for good Canonical discussion.)
Toward the end of this season 'Elementary' has found a balance it lacked for most of the first two seasons and part of the third. Where fetishise and quirks had become the norm for Millers Holmes, we now see a more balanced individual. Even if he is not as Sherlock Holmes like as we would, well, like. That should be the goal for season four. It makes for good discussion try to come up with how that could happen.
And for once, in this episode, there were no murders.
I am hopeful that the cliff hanger is something other than his return to addiction, that's just in my nature. The cliffhanger is also bringing Holmes father over for a visit.
Canonically we could suggest the heron den was a refernce to TWIS.
I did find the episode interesting, but once again because of the lack of Sherlock Holmes traits (habits,etc.) in Millers Holmes I can only fairly give it;
I do however think the show is on an upward swing.