The CW has released the plot synopsis for the upcoming ninth episode of "Arrow's" second season and it looks like the mid-season finale will feature an interesting DC Easter egg. Titled "Three Ghosts," the episode is described as follows:
"After a fight with Cyrus Gold AKA the Acolyte (guest star Graham Shiels), Oliver is drugged and left for dead. Determined to cure him, Felicity makes a risky decision. The cure causes Oliver to hallucinate, and what he sees forces him to confront his past. Meanwhile, Barry (guest star Grant Gustin) continues to help Felicity, and their connection grows stronger. The Arrow asks Lance to look into Gold, but when the stakeout on Gold goes bad, someone is killed. Roy (Colton Haynes) is captured and tortured by Brother Blood (guest star Kevin Alejandro). John Behring directed the episode with story by Greg Berlanti & Andrew Kresiberg and teleplay by Geoff Johns & Ben Sokolowski."
You might be saying that "Solomon Grundy isn't mentioned" above, but Cyrus Gold was Solomon Grundy's human name when he was still living and not yet the zombie-like supervillain we know him as today. It remains to be seen if Gold will transition into Grundy in the series, but with the introduction of superpowers coming up soon, it's not entirely out of the question.
In addition to Gold, "Arrow" has heavily expanded its comic book roster to include Summer Glau as Isabel Rochev, Caity Lotz as Black Canary, Michael Jai White as Bronze Tiger, Kevin Alejandro as Sebastian Blood, Bex Taylor-Klaus as Sin, Dylan Neal as Dr. Anthony Ivo, Katrina Law as Nyssa al Ghul and Grant Gustin as Barry Allen/The Flash.
"Arrow" airs Wednesdays at 8 P.M. ET/PT on The CW.