Sherlock immediately moves to catch them both - splaying his legs to hold both their weight before allowing Howard to shift up. He doesn't answer immediately, but under his breath he starts to hum, and then a little louder, to sing.

"One man went to mow, Went to mow a meadow... One man and his dog, Went to mow a meadow." His voice was deep but and oddly naive in a strange sort of way, as if he had stopped trying to sing as a child, but had been trained, once upon a time. He took a breath, and a little louder, continued.

"Two men went to mow, Went to mow a meadow. Two men, one man and his dog--"