Mycroft Holmes is the elder brother of Sherlock Holmes. He possess the same powers of observation as his younger brother; however, he lacks the energy to put them to the same task as his brother.
"...he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right. Again and again I have taken a problem to him, and have received an explanation which has afterwards proved to be the correct one. And yet he was absolutely incapable of working out the practical points..."
— Sherlock Holmes, speaking of his brother in "The Adventure of the Greek Interpreter"