Holmes would have interrogated Lestrade as he climbed the ladder, had not the inspector had the good sense to withdraw from the hatch. As it was he had the questions he wanted to ask rattling around inside his head. Is Watson alive? Is he unhurt? Where did you find him? How on earth does he manage to climb one of these things without losing a grip on this cane?
As he emerged onto the street he saw Lestrade ordering several constables to go and close the manholes they'd opened. And beyond Lestrade, a police wagon, the door hanging open. There.