Mycroft paused, turning when he saw a shadow pass in front of him, following behind the tech. He crept up behind them, just in time to see the tech try to move ahead of Lestrade - oh the idiot was trying to be a hero, Lestrade reaching him to grab him and drag him back, just as he saw an arm snake out of a sideroom, with a gun. The gun fired, Lestrade jerked, and Mycroft was already moving.

The only warning the shooter got was, "BALL!" as Mycroft's umbrella swung up and smashed the perpetrator in the face with the hard wooden handle. The gun went flying as Mycroft stepped back and jabbed the handle into the shooter's throat, then down into his, or her, stomach, as hard as he could, incapacitating the shooter as best he could. The shooter fell with an 'oof', and Mycroft darted off behind the doorway, slightly breathless as he wrapped his arm around Lestrade's waist, pulling him off the tech, and towards the safety of the door.

"Come on, grab him, and lift! Carefully!" He growled, before whispering to Gregory, "Lestrade, if you die on me, I am going to be unbelievably cross with you."