The frown on Mycroft's face became more pronounced. He didn't like being put back on his heels, even a little bit. John knew that he was valuable, and John knew that he knew. That much was obvious.

"And what makes you think that I can simply find a way for my brother to miss what could be months of work? Who could take over on such short notice? who will handle his bills? I don't think that you have thought these logistics through. It has taken weeks to get this group of experts together. I can't just add someone at the last minute."

In fact, Mycroft had known that John would want Sherlock to come along, and had already discussed it with Lestrade, though he had- not accidentally- not discussed any of this with Sherlock yet. The trip was still unknown to him.