After Laurel was laid to rest in the previous episode, the team of heroes will continue the fight against Darhk on "Arrow" season 4 episode 20. The next episode is titled "Genesis" after Darhk's operational plan against Star City.

Operation Genesis has been mentioned several times in the season as Darhk's ultimate dark plan against Star City. There have been several flashbacks of Oliver shown througought the season when he was in a facility owned by H.I.V.E. The powerful relic that Darhk is after was first seen by Oliver during his stay there and it is the key to the operation.

The trailer opens with Oliver saying "There is no length that I will not go to, to avenge Laurel … to stop Darhk from hurting anybody again." Diggle, who feels that Laurel's death is on him, for choosing to believe his brother, gets a lead of Andy's whereabouts only to be lured into captivity.

A scene shows Diggle tied with his hands above him and Andy says, "Mr. Darhk is on his way, I'm supposed to prep you," while stabbing Diggle with a sharp object. It remains to be seen if Andy's alliance with H.I.V.E. is a choice he consciously made or if he is under some spell.

Thea and Alex are on a vacation that will be cut short as it would seem like Darhk's plan has also included nearby cities.

Meanwhile, Oliver and Felicity will work together to find a magical solution to defeat the enemy. Oliver has previously revealed that he has encountered the artifact before. Many Olicity fans are hoping that with two more episodes left in the season, the pair will reunite as they clearly still love each other.

Meanwhile, title for episode 21 has been revealed as well. "Monument Point" will feature the team still looking for ways to defeat Darhk and will seek the help of Felicity's father. A big revelation is expected that will be a primary focus in the next season.

"Arrow" airs Wednesdays, 8 p.m., on The CW network.