"Arrow" has been on a short break since Season 4 episode 15 "Taken" was aired, and the upcoming Season 4 episode 16 "Broken Hearts" will air Wednesday, March 23. The episode is expected to take fans one step closer to learning who is in the grave.
We had eliminated Felicity (Emily Bett Riackrds) from the list of characters heading to the grave following the preview of the car scene featuring Oliver (Stephen Amell) and Felicity. However, new fan theories suggest despite Felicity being present in the car with Oliver, she could still be dead. DeithWX explained in a Reddit discussion Felicity in the car could just be a hallucination of Oliver, much like Shado (Celina Jade) was of Slade (Manu Bennett).
Fans will remember how Slade used to have visions of Shado telling him to kill Oliver after Mirakuru was injected into him. From Oliver's flashbacks at the island, it is clear Oliver still gets visions of Shado as well. Some fans believe Oliver could very well see Felicity in the place of Shado, with his affections having shifted from Shado to Felicity.
Meanwhile, other fans remain adamant it is Quentin Lance (Paul Blackthorne) who is in the grave. Arrowknight06 highlights a conversation between Oliver and Lance from episode 1 of Season 4, where the latter blames Oliver for bringing darkness into Star City.
The fan adds Oliver's words to Barry (Grant Gustin) while standing by the grave "I brought this darkness upon us... Now I know It's not my fault. It's my responsibility," is clearly an Easter egg for what had happened earlier.
We cannot completely rule out other characters like Laurel and Diggle, but if the hallucination version of Felicity proves to be wrong, Lance remains the top contender for the grave.