Roy Harper (Colton Haynes) breaks into a facility to learn more about the Mirakuru serum in the first clip from Arrow's mid-season finale, "Three Ghosts", airing Wednesday, December 11 at 8 PM ET on The CW. Although the exact properties and purpose of Mirakuru (a.k.a. The Miracle) are not known yet, it is a serum used by Brother Blood (Kevin Alejandro), which has caused those who are given it to suffer severe convulsions. Watch what happens when Roy gets caught in the act before tuning in tomorrow night.

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 is captured and tortured by Brother Blood (guest star Kevin Alejandro).