5. The Demon

Complete story — includes the ending

After having seemingly been broken, Oliver is introduced to Level Two, a secret facility below Slabside, where inmates are kept in inhumane conditions and forcibly become experimental test subjects overseen by Dr. Jarrett Parker. He discovers that Talia al Ghul is the Demon. He reluctantly teams up with Talia to plan an escape, but decides not to escape himself to avoid having to spend the rest of his life as a fugitive. After collecting evidence of what happened in Level Two, he asks Talia to deliver it to Felicity, causing the facility to be shut down and Oliver to get transferred back to Level One. Though Talia gets her revenge on a now-fired Dr. Parker by ambushing him while he was loading his car. Elsewhere, Curtis gets back in the field with Diggle and helps capture an international terrorist following a lead from the Zürich bank. Curtis discovers that A.R.G.U.S. is trying to get rid of the terrorist's possessions and recovers a painting of Dante Alighieri. Laurel plans to use the evidence that Oliver collected to plead for his release.