Colonel Ross still wore an expression

Colonel Ross still wore an expression which showed the poor opinion which he had formed of my companion’s ability, but I saw by the inspector’s face that his attention had been keenly aroused.

“You consider that to be important?” he [Inspector Gregory] asked.

“Exceedingly so.”

“Is there any point to which you would wish to draw my attention?”

“To the curious incident of the dog in the night-time.”

“The dog did nothing in the night-time.”

“That was the curious incident,” remarked Sherlock Holmes.

Inspector Gregory and Sherlock Holmes in “Silver Blaze”