Things look pretty bad for the gang on “Arrow” as Season 4 barrels toward its final episodes. Now, its members will have to take on a mad scientist who previously showed up to wreak havoc on Central City and the team on “The Flash.”

“The Walking Dead” star Emily Kinney will reprise her role as Brie Larvan, a former employee of Mercury Labs who specialized in the development of robotic bees that she weaponized. In “The Flash,” Season 1, episode 18, titled “All Star Team Up,” Larvan appeared at the same time as “Arrow” characters Felicity Smoak (Emily Bett Rickards) and Ray Palmer (Brandon Routh). With the help of the scarlet speedster, they put the madwoman in jail, but it seems she’s escaped and will come looking for revenge in the next episode of “Arrow.”

According to the plot synopsis for “Arrow” Season 4, episode 17, titled “Beacon of Hope,” Larvan will be accompanied in Star City by some new and improved killer bee robots. The episode will see her take over the Palmer Tech building, which happens to be hosting Felicity, Thea (Willa Holland) and Donna (Charlotte Ross). All Larvan wants in exchange for her hostages’ lives is the implant that’s been put in Felicity’s spine allowing her to walk again. Interestingly enough, the CW’s synopsis teases that the gang will have to turn to an unlikely ally to help them rescue the trio, but it fails to elaborate on whom that ally might be.

To find clues, one must turn to the teaser trailer for the coming episode, which shows Oliver (Stephen Amell) take a stinger from one of the villain’s robotic bees. Larvan warns it packs a bigger punch than a natural bee does, and Curtis Holt (Echo Kellum) reveals that the robots are capable of somehow replicating inside the human body, which puts Oliver out of the game and explains why the team will need an extra hand to save the day.

The series has been slowly incorporating Holt into more plotlines. He’s become one of Felicity’s best friends and has endeared himself to the rest of the group in many ways throughout the season. It’s unclear from the trailer alone if he’s helping a hostage who’s been stung in the Palmer Tech building or whether the unlikely ally is Holt being brought on as an official member of Team Arrow. After all, the character was plucked directly from the pages of the comic books as the alter ego of the DC Comics character Mr. Terrific. Maybe Team Arrow will realize his special skills could prove useful in stopping Larvan from killing some of Palmer Tech’s most valuable employees.

The new episode of “Arrow” premieres on the CW Wednesday, March 29, at 8 p.m. EDT.