'Arrow' season 4: Who lies in the grave?

"Arrow" season 4 will return on Jan. 20.Arrow/Official Facebook Page

As "Arrow's" season 4B premiere is just hours away, fans are already excited to see the gang back in action and what the rest of the season would bring to the table.

The grave seen in one of "Arrow's" previous trailers is one of the biggest mysteries of the show since it went on its winter break. Based on the latest trailer for the midseason premiere, there are several potential candidates as to who will be on that grave Oliver was standing on, including Laurel (Katie Cassidy), Thea (Willa Holland), and Felicity (Emily Bett Rickards).

In the trailer (below), Thea is seen hanging from a roof with Oliver holding on to her; Laurel is bloody; and Felicity is in a bad shape.

However, TV Line also provided an explanation why it is unlikely that they will die. For instance, the grave could not have belonged to Thea because a surviving family member needs to be with Oliver.

It is also expected that if Felicity died, Oliver would have shed more tears since they are recently engaged. On the other hand, it couldn't have been Laurel because she recently took her sister's place as Black Canary.

The long wait will soon be over and fans will finally know the answer when "Arrow" returns tonight. Apart from the much anticipated reveal, the second half of season 4 also promises more explosive action and dark twists to the DC-based series.

Felicity is still not better, but the preview shows she is suited in her usual hacker outfit. However, it remains to be seen if her appearance in the trailer is a flashback or if she really will be back to work.

The promo trailer also revealed the comeback of some characters as they engage in a battle against Damien Darhk (Neal McDonough). They include Roy (Colton Haynes), Nyssa (Katrina Law), and Katana (Rila Fukushima).

As for Darhk, he is determined to keep to his promise of having a "new beginning" once he succeeds in bringing the world to an end. He was also seen sending an arrow flying to hit the Green Arrow.

New episodes of "Arrow" will air starting Wednesday, Jan. 20, at 8 p.m. EST on The CW.

Arrow Midseason TrailerYouTube/TheCW