“An Infinite Capacity For Taking Pains” is a telling title. It’s a quote close to Sherlock’s heart (episode writer Bob Goodman had Sherlock advise Kitty to “accept that you’ll be taking pains” in the third season). It’s also a paraphrase of this Carlyle quote about Frederick the Great—the saying is more popular than the actual quote but inexact, which perfectly suits an episode where Sherlock has to deal with the idea that soon he might be as fallible as anyone else.

But the context around the quote—while essentially a blurb for the monarch in question—is also relevant here. Elementary has spent five seasons tracking a continual pull on Sherlock. His sobriety isn’t backstory or part of a superhuman skill set; it’s something that demands all the patience he has and more. He’s tempted and tested himself to prove he’s as strong as he thinks, and he has also faltered. Facing down post-concussion syndrome with no sense of when it will get better, if it ever gets better, is going to require all his capacity for taking trouble.

I recapped the season premiere of Elementary for The AV Club.