I grinned. ‘Why, Holmes. You’ve been swotting up.’
‘Astronomy - nil,’ he quoted, with a laugh. ‘It’s hardly good business to advertise one’s weaknesses. Proving another’s misconceptions wrong, however, is. I have taken advantage.’
‘Show me, then. What else have you learned to prove me wrong?’
'The constellations,’ Holmes murmured. His voice was close against my ear. ‘The stars.’ His long hands gestured toward the sky, as though directing the heavens, and my heart, having been quiet for so long, leapt into beating.
Holmes in the canon does laugh, sometimes softly and sometimes quite joyously, and I loved finding those moments in him. I love this moment in particular because it's the happiness and gentleness that really kickstarts Watson's deeper feelings, and although it does become difficult and dangerous between them, I think it's still always circling back to these kinds of moments: moments they are just together, and it's easy and content.
Those are the moments they build the most strength together, and it's just really lovely to find those bits and pieces in a story that does have to deal with some of the realities of the time.