John Barrowman
"Arrow" star John Barrowman, pictured here as Malcolm Merlyn in the "The Flash" crossover in 2015, may be the person responsible for the now infamous grave scene teased at the beginning of Season 4. The CW

Throughout Season 4 of the CW’s “Arrow” a major character death has been teased in a flash-forward sequence set six months after the premiere. Whoever ends up in the grave prompts Oliver (Stephen Amell) to vow to return to a life of murder, and the most recent episode of the show gave a hint as to who his target may be.

Ever since the grave was teased, fans have been speculating rampantly about who may end up dead when the time comes. Despite all the theorizing, many assumed that the person responsible for killing someone so close to Oliver and Barry Allen (Grant Gustin) was the Season 4 bad guy Damien Darhk (Neal McDonough). However, with the latter half of Season 4 in full swing, episode 12 saw the magical baddie take a bad seat to another villain that’s been lurking in the background all year.

When Nyssa al Ghul (Katrina Law) escaped the League of Assassin’s captivity, she went to Japan in search of two things: vengeance and a magical elixir called the Lotus. The episode ended with her promising Oliver that the Lotus could save his sister, who is dying from her previous brush with the Lazarus Pit. In exchange for it, she demands that he kill the leader of the League, who also happens to the father of Oliver’s sister, Malcolm Merlyn (John Barrowman).

As diehard fans of the show will remember, Merlyn ended up being the main bad guy of Season 1, forcing Oliver to up his game as the Green Arrow in order to finally stop the formidable opponent. Since then, he’s been lurking in the background of all of Team Arrow’s dealings, having formed a reluctant truce thanks to his daughter, Thea (Willa Holland). However, last night’s episode saw Thea’s health take a major dive from the effects of the Lazarus Pit. With her gone, all Merlyn would be to Oliver is a nefarious villain that’s partially responsible for his father’s death, countless murders and commands the most powerful army of killers in the world. In other words, a pretty straightforward target for the Green Arrow. While this doesn’t give any more clues as to who is in the grave, it does mean that Oliver’s list of bad men to stop has gone from one to two.

TV Line compiled all the potential victims that could be in the ground in the Season 4 finale and both Nyssa and Thea, both of whom are directly connected to the Merlyn storyline, were near the top of their list. If Nyssa’s caper to have Oliver end Malcolm’s life results in a battle with the villain, odds are good the body count will be high.

If the rumors end up true and Oliver is set to go after Merlyn in the season finale, the question then becomes: What happened to Darhk? The character hasn’t made any big moves against the city after tipping the team off to his plan to unleash a deadly toxin on it. If Oliver is battling a war on two fronts, it seems he may need to take down his magical villain and his arch nemesis before Season 4 draws to a close.

"Arrow" airs Wednesdays at 8 p.m. EST on the CW.