Felicity asked for father's help while Oliver was shaken in "Arrow" season 4 episode 21.

"Arrow" season 4 episode 21 is entitled "Monument Point." According to Spoilers Guide, Felicity realized that she had to go to her father Noah Kuttler and ask the latter's help, after the team knew about Damien Darhk's next plan. As per the publication, the episode also saw a one on one talk between Felicity's father and Oliver, who is left rattled.

In the episode, Darhk started to gain control over the planet's nuclear missiles and this led Felicity to seek help from Noah, who can help dismantle the Rubicon. The villain also sent Michael Amar and Brickwell to search and kill Noah, who lives in an old cabin. Luck was in Noah's side, as he was saved by Oliver and the team from Darkh's men.

After the rescue, Noah agreed to help the team and told them that the needed a high-powered processor, which is located in Palmer Tech. Since Felicity was fired as CEO from Palmer Tech, the team was left with no choice but to break in and steal the tech.

Meanwhile, H.I.V.E. discovered a base location after hacking Rubicon. This is followed by an attack, but Felicity and Noah managed to shut down the Rubicon, halt the missiles, and causing them to head to the Monument Point. Felicity made an attempt to change to course of the missile, but she was only able to reroute it to a less populated town.

In flashbacks, Reiter also managed to escape the caves; however, Oliver and Taiana the prisoner got the idol once more.

Moving forward, Oliver is set to fight for Thea while Donna Smoak comes face to face with Noah in "Arrow" season 4 episode 22. According to Spoilers Guide, Oliver and Diggle are set to save Thea after the incidents that took place in "Monument Point." In addition, the quest to stop Darhk continues with Felicity, Noah, and Curtis.

"Arrow" season 4 episode 21, "Monument Point," aired on May 11 while episode 22, "Lost In The Flood," is set to air on May 18.