Study in Terror, A 
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Sherlock Holmes: My dear Mycroft, this is a surprise! Watson, some sherry ... Is this a social call?
Mycroft Holmes: Yes, yes, oh yes, purely social.
Mycroft Holmes: How are you?
Sherlock Holmes: Very well.
Sherlock Holmes: Well, now that the social call is over, hadn't we better get down to business?
Mycroft Holmes: For Heaven's sake, stop sawing away on that infernal instrument! It was a sad day when Mother gave it to you, a sad day for her, a sad day for you, a sad day for us all ... What I cannot understand is why, since you've had that violin with you so long, you never learned to play!