Obviously Sherlock doesn't have to be there. It's Joan and Ted that they're excited about, because of the connection to Richmond and Rupert and all that. And Ted especially won't be able to avoid it anyway, since it's part of his job. So it's better to get out ahead of it.

"Mmm," he agrees, getting out his phone to text Keeley, figuring she'll have his number. I'll call after we finish dinner."