The reaction to Molly this series has completely taken me by surprise. I did my day or two filming, like last time. But this year - because of the frankly brilliant writing - I think people have noticed her. Which is amazing. Molly works because, while Watson is “the audience”, Molly is every woman of a certain age sitting at home on the settee fantasising about running their hands through Benedict Cumberbatch’s hair. Which is basically what I’d have been doing if I wasn’t in the show… Also, I think most people have experienced the agony and the ignominy of unrequited love… I’ve never thought Molly was an idiot. She just really, really loves him.

Louise Brealey: 'I don't think Molly is really Sherlock's type' ›

Molly just automatically cast herself out and Sherlock looks like he’s just realized Molly has feelings. I can imagine memories go through his mind, from “Black, two sugars please. I’ll be upstairs” to “Gay” to “Cancel it, you are having lunch with me”. He’d treated Molly so carelessly but that’s normal because that’s how he treats everyone, well, almost everyone. He’d mocked and hurt her without meaning it for perhaps many many times because sentiment isn’t his area. But at that moment Molly sees him through, maybe not entirely, but more than Sherlock would ever expect. And that resulted in me having lots of Molly feelings….

Molly was a little awkward when she said “I ended it”, because it was practically Sherlock who ended it with, you know, “Gay.”

Sherlock: Molly!

Molly: Hello, I’m just going out—

Sherlock: No, you’re not.

Molly: I’ve got a lunch date.

Sherlock: Cancel it. You’re having lunch with me. *pulls out two bags of chips and waves them*