My attempt to patch my headcanon that Mycroft loves musicals; also, my homage (several years too late) to the jam meme (my theory is that the Holmes parents, while otherwise very normal-looking, are absolute geniuses with food).
Alternate names for "Anthea" included Erin Norton, Monica Penelope, and Miss Mawdsley. I remain convinced her job title is Mycroft's Chief of Staff, even if she's actually the only member of that staff.
"No, sir, I will not take your parents to see Les Misérables for you."
"Why not? You might actually enjoy the show."
His chief of staff, a woman who had once introduced herself as Anthea, silently regretted the day she had mentioned the show (or indeed her fondness for musical theatre) to him. Sometimes he was just an unbearable snob. God forbid he ever learn she actually liked Phantom of the Opera unironically.
"Why would they want to see it with me? You're their son. They miss you and would like to spend some time together with you since they're in the city. They're not here to see me, they want to see you. The show is just a bonus."
"You know my parents are quite fond of you," said Mycroft, trying to change the subject. "I remember they sent you a scarf for Christmas. And some jam too. I'm sure they'd be pleased to see you again." A pause, then he played his final card. "Don't we have a conference call with Japan that day?"
"I've already scheduled around it," she said immediately. "Look, sir, you've been through worse. It's just three hours with your family."
"Three hours of feelings," said Mycroft in disgust. His face could have sunk all thousand of Helen's ships. "Sentiment. You might as well sit through treacle."
She had once accompanied him to a London production of Chess, which she had been told was his favorite show. It could certainly not be described as "treacly" at all.
"I thought you liked treacle," she said. Her superior's sweet tooth was quite well-known among certain circles.
"Not like this," said Mycroft. "The last time I saw Les Misérables, I -" He stopped abruptly and coughed delicately. "Fine, if you go with my parents I'll give you the day off. The rest of that week off, even."
"I can't, I have two meetings with the Americans that can't be moved," she said automatically, before Mycroft's words caught up with her. "Wait, 'the last time you saw Les Mis'? If you've already seen the show, how bad can it be? You already know what happens."
"That's the problem. Everything's going so well, and then they all start dying once the second act starts. I can't take it. It stimulates my sinuses, you know how they get."
In all the time she had worked for Mycroft, she had never seen him cry, let alone suffer from allergies; in fact, she'd been wondering if the man even possessed tear ducts. This sudden assertion seemed dubious, at best. She hummed a few notes experimentally: empty CHAIRS at empty tables...
Mycroft sniffed suspiciously. His lip trembled, and there was a sheen in his eyes she had never seen before.
She passed him the box of tissues.
"What do I have to do to get you to take my place?" He sighed, and looked at her searchingly. "Oh. Oh. My parents already spoke to you, haven't they? What did they offer you?"
"Some of your mother's home-made jam."
He groaned. "My mother. I should have known." His tone, in anyone else, would have been despairing; one would think he was talking about the fall of nations, rather than the fleeting loyalties of one overworked chief of staff. Faced with his obvious distress, she took pity on him.
"Look, sir, your parents are coming to town, and they expect to see a show with their son. If you really want to get out of this, you do have a brother. Your parents haven't seen Sherlock in a while, either." He wouldn't be any more successful in getting Sherlock to do what she had refused to - he was even more of a musical snob than Mycroft was - but she decided against mentioning that now. She could practically taste that jam already...
"He's in Serbia now, isn't he? Yes, we might as well call him back now, the PM's been nagging me about that underground business, and it's not like he's doing much where he is anyway. He'll be much more useful at the theatre." Mycroft smiled benevolently, the world arranged to his purposes again. "Thank you, my dear, you always manage to arrange things so neatly."
"Of course, sir." Well, what he didn't know wouldn't hurt him. She pulled out her phone.
Mrs Holmes, don't worry. He'll be there, she typed, deliberately leaving "his" identity vague.
And what happened the last time Mycroft saw Les Miserables?