Arrow: Charlotte Ross Says Donna Will Reveal A Family Secret To Felicty

Last week, Arrow guest star Tom Amandes hinted to ComicBook.com that there might be more to the relationship between Noah Kuttler (The Calculator, played by Amandes) and his daughter Felicity Smoak.

"Well, each time I've come on, I've learned a little bit more about Noah, and so has the audience," Amandes said last week. "What's been fun and gratifying about these next two episodes is that you get a little better sense of the family dynamics of the Kuttler/Smoak family."

Now, Charlotte Ross -- who plays Felicity's mother -- is teasing the revelation of a family secret. Coincidence? Likely not.

"There is something that Donna has kept hidden for many, many years and she decides to, finally, come clean to Felicity about it — even though she knows she may risk losing her by doing so," Ross told TVLine of tonight's episode, titled "Lost in the Flood." "Being a single mother myself, many things Donna feels and the choices she has had to make really resonate with me. And because [Emily Bett Rickards] and I have grown so close, it just felt so deep, honest and intimate when we were shooting the scenes in this episode. [Our on- and off-screen bonds] really have become intertwined in a way that has made our work together much richer than I could've hoped."

The episode centers on Kuttler and Felicity struggling to stop a nuclear attack by Damien Darhk and Felicity's ex-boyfriend, while Team Arrow focuses on trying to rescue Thea from Merlyn and H.I.V.E.

Arrow airs on Wednesday nights at 8 p.m. ET/PT on The CW. Tonight's episode, "Lost in the Flood," is the penultimate episode of Season Four -- and like all penultimate Arrow episodes, is named after a Bruce Springsteen song.