"Arrow" Season 2, Episode 8, "The Scientist" is the penultimate serving of Oliver Queen and DC Comics friends in 2013. Oliver and Felicity (Olicity to shippers) meet another DC hero, who is about to have his own series in The CW. Arrow fans are all set to watch "Glee" alum Grant Gustin as Barry Allen aka The Flash.

Spoiler alert: This feature contains minor spoilers from "Arrow" Season 2, Episode 8, "The Scientist," as well as major spoilers from Arrow 2x07, "State v. Queen." The new episode airs on the U.S. network The CW on Wednesday, Dec. 4.

Olicity fans cheered two weeks ago as Oliver Queen (Stephen Amell) saves Felicity Smoak (Emily Bett Rickards) from The Count (Seth Gabel). Despite swearing in memory of Tommy Merlyn that he won't kill again, Oliver realizes there's no choice when Felicity's life is at stake. Coincidence or not, the episode shows another Merlyn, The Dark Archer himself. (Whether it's "Dr Who" or "Arrow," John Barrowman always receives a warm welcome from avid fans!)

In Arrow 2x08, Felicity will show a certain fondness for Barry Allen, and Oliver won't be pleased about it. Watch the YouTube video (sneak preview) below or follow this link. Felicity seems to be hinting that The Flash will come to Oliver's rescue.

Stephen Amell has only positive things to say about Grant Gustin as The Flash. In the FOX show "Glee," Grant became popular as Sebastian Smythe, former lead singer of The Dalton Academy Warblers. Many DC fans have judged the young actor too soon, saying that the kid couldn't pull off a compelling Barry Allen vibe. The Dec. 4 Arrow episode can make or break Gustin's chances at getting a strong pilot audience for his own DC series on The CW.

#Arrow has 2 more episodes. Tomorrow & December 11th. Then we'll be back in a... (Hurry.......?)

— Stephen Amell (@amellywood) December 4, 2013

The last Arrow Season 2 episodes of the year 2013 will feature Grant Gustin as Barry Allen aka The Flash. Contrary to previous reports, there will be no third appearance from Gustin. At least not in this season. "The Flash" producers have decided to do a traditional pilot offering. (No backdoor launch.) Watch this sneak peek of Arrow Season 2, Episode 8. This video shows the first encounter of Grant Gustin as "The Scientist" and Stephen Amell as Oliver Queen. Amell himself promotes this clip online.

Hmm..? No. No idea. Less than 2 days. #Arrow http://t.co/qFcLO96cwT — Stephen Amell (@amellywood) December 3, 2013

Will it take some time before fans could see John Barrowman in Arrow Season 2? Or will The Dark Archer and The Flash have an exciting encounter? A lot is expected from Arrow 2x08. Cliffhangers have been a staple component to each Arrow episode lately. Still, it is safe to assume there'd be bigger jaw-dropping moments coming up.

More Arrow Season 2 Spoilers and TV Guide Features:

'Arrow' Season 2, Episode 7, 'State vs Queen' Spoilers: The Count, Vertigo, and a Death Sentence [VIDEO]
Revenge Season 3 Spoilers: Who Shoots Emily Thorne On Her Wedding Day? [WATCH]
'NCIS' Season 11 Spoilers: Ziva Fans Let Go; Ellie Bishop Love Angle with Gibbs or DiNozzo? [VIDEO]