It's another week, folks, and that can only mean one thing — a fresh new chapter in the ongoing Twitter saga that is J.K. Rowling vs. Donald Trump.

This time, the topic in question was a current favourite of the president's: fake news.

On Monday, he went on one of his typical early morning Twitter tirades, this time attacking "negative polls" regarding his attempts to implement a travel ban.

Any negative polls are fake news, just like the CNN, ABC, NBC polls in the election. Sorry, people want border security and extreme vetting. — Donald J. Trump (@realDonaldTrump) February 6, 2017

Rowling's response was as swift and savage as ever.

Can you imagine the number of mirrors this man must have smashed? https://t.co/TPS8XDuAmm — J.K. Rowling (@jk_rowling) February 6, 2017

This time — as well as the usual support from fans — she also received some well-timed back-up from Ricky Gervais.

Any tweets that don't agree with my tweets are FAKE NEWS! — Ricky Gervais (@rickygervais) February 6, 2017

Soon, the mirror jokes had started.

@jk_rowling He'd have to have someone do it for him. His tiny hands couldn't break a mirror. — Scott Springer (@scott_springer) February 6, 2017

@jk_rowling mirror mirror on the wall, who has the biggest hands of all? — Katie MacBride (@msmacb) February 6, 2017

@jk_rowling What do you think he sees when he looks into the Mirror of Erised? A positive poll? — Joel Gleicher (@JoelG_88) February 6, 2017

When it comes to Twitter, J.K. Rowling is an unstoppable force.