He's deep in campaign planning with his brother when the first text arrives.
Need me?
Why not? he texts back, candidly ignoring Mycroft's questioning look.
What will I get out of it?
He chooses every word carefully as he types the reply. Your heart's desire.
Three days later she shows up at his flat, and he quite enjoys the sight of his dear brother thrown off balance for what is probably the first time.
"This is not possible. You were dead, I checked."
Irene Adler graces him with a sympathetic smile. "Looks like Junior put one over you after all."
"No time for flirting, Woman," Sherlock cuts in wryly. "What do you have for us?"
She throws a sealed envelope onto the desk. "Birth certificate of James and John Moriarty, born in Dublin in 1976."
Mycroft raises a sceptical eyebrow. "Twins? There's nothing about it in our files."
"Well, I know someone – know what she likes, actually."
His brother rolls his eyes in annoyance, while Sherlock picks up the envelope. "Which of them is still alive?"
"John, I guess. Both of them went by the name of Jim for many years now. Like in The Prestige film, you know."
It's Irene's turn to roll her eyes when she eventually figures that he doesn't have the slightest idea of what she's talking about. "Never mind. The point is, there never was one consulting criminal. Each of them played the part in turn, until Jimmy boy decided to blow his brains out on the rooftop of St Bart's Hospital. Johnny boy has been lying low ever since, but now he's back to playing the game."
"And my little brother has suddenly decided to enlist the help of one of Moriarty's protégées. A brilliant idea indeed, Sherlock."
"Shut up, Mycroft. Back to business now."
Irene smirks at either of them in turn and promptly vanishes out of the door.
xxx
He can't be one hundred percent sure whether this is just a bluff on the Woman's part – perhaps it's a double bluff, maybe even a triple bluff – but on balance of probabilities he knows she's their better option. Moriarty welcomes her back with open arms; he also seems to buy the story that she's after revenge now.
Mycroft's men are keeping Sherlock's friends under strict surveillance. There's an entire team that is currently positioned at John and Mary's house, while another has settled in the immediate vicinities of 221B Baker Street.
Lestrade isn't in the slightest happy about moving in to John's old room, but Mycroft can be very persuasive when he wants to be. At least Molly doesn't make too much of a fuss when he requires her to share Mrs Hudson's apartment, and that's something given the intricacies of the whole situation.
Irene's text comes at long last, and he heaves a sigh of relief.
Leinster Gardens. Come alone.
He doesn't tell Mycroft, though he can feel his penetrant stare as he sneaks out of the room.
If there's anything that his confrontation with Magnussen has taught him, is that there's nothing he wouldn't do to protect his friends. He's well prepared to kill his opponent, or die at his hand if it needs be.
That's why he simply closes his eyes when Moriarty welcomes him by pressing the barrel of a gun to his temple. "Go ahead. You won't have to burn my heart if you do."
"Your heart isn't the only one I'd like to burn, Sherlock," his enemy sing-songs, only to trail off as a gunshot echoes against the walls.
Moriarty slumps to the floor, and he stares across his dead body to where Mycroft is standing in the shadows.
"I had no idea you were such a marksman, brother mine."
"MI6, remember?" that's all Mycroft says before he turns on his heels and disappears into the darkness.
xxx
It's in the dead of the night when he wakes up to find the Woman standing in the middle of his bedroom.
"What do you want?" he mutters grumpily, and she gives him an indulgent shake of her head.
"I'm here to claim my prize. A pity for the kid downstairs – she seems quite eager to have dinner with you, if only you'd have her."
"I never said we would be having dinner."
Her eyes narrow dangerously. "You should know better than to trick me, Mr Holmes."
"I promised to give you your heart's desire. Here it is," he states in the bored tone he usually reserves for Scotland Yard, handing her a slip of paper.
"What's that supposed to mean?"
"Gail Norton. I've traced her whereabouts. Thought you might be pleased to see her again."
He's obviously caught her off guard, and for a fleeting moment she looks like any other woman nursing a broken heart. Her mask is back in no time, but he knows that counts as another victory on his part.
"You're a strange man, Sherlock Holmes," she says as she pockets the note and walks away.