Prepare for an Arrow mini-crossover early in the fourth season of The Flash.

It was announced today that Emily Bett Rickards will bring her Arrow character, Felicity Smoak, to The Flash for the new season’s fifth episode, titled “Girl’s Night Out.”

While the Arrowverse shows on The CW are known for their yearly crossover stories, this also isn't the first time that Felicity has gotten ahead of the game with a mini-crossover like this. She also appeared on The Flash first season episode "Going Rogue" as well as the third season episode "Paradox."

As for this year's big crossover, the "brain trust " for the event, which will also encompass episodes of Supergirl and DC's Legends of Tomorrow, only recently convened. Last year's crossover saw the heroes teaming up to battle alien invaders, so it will be interesting to see how they top that this time around.

The episode will also feature Battlestar Galactica alum Katee Sackhoff as the villain Blacksmith. Blacksmith runs a black market for supervillains and “uses every means possible, including the long list of metahumans under her thumb, to ensure her illicit enterprise thrives.”

Blacksmith is just one villain confirmed the fourth season of The Flash. The series has also cast the DC Comics villain Hazard as the season's big bad, The Tinkerer, and Danny Trejo as an interdimensional bounty hunter, but they're going to need more bad guys than that, and we have some ideas about who they should choose.

The Flash returns for its fourth season on The CW on Tuesday, October 10th at 8 p.m. ET.

(via Entertainment Weekly)