‘His Last Vow’ airs at 8.30pm tonight on BBC One and stars Lars Mikkelsen as Charles Augustus Magnussen.

Speaking at BAFTA in London earlier this week to an audience of fans and journalists, including CultBox, Moffat confirmed: “We’ll be back, fairly obviously… We’ll get them made as quickly as we can!”

The writer revealed: “Rather excitingly, Mark [Gatiss] and I, for no particular reason, we just got out of the rain and sat at the top of the [Sherlock] production bus and we just started plotting out what we could do in the future – and we plotted out the whole of Series 4 and 5.”

He added: “…I think we’ve got some crackers. The ideas we had that day, I thought, were the best we’ve ever had.”

Update [Monday 13 January 2014]: The BBC’s Press Office told CultBox today that, despite Steven Moffat’s announcement, there is “nothing the BBC can say officially as yet”.

> Find out everything we know so far about Series 4 in our news summary.

What would you like to see in Series 4 and Series 5? Let us know below…

> Order Series 3 on DVD on Amazon.

> Buy the Series 1-2 boxset on Amazon.

Watch the Series 3 teaser trailer…