"Arrow" is heading towards the end of its fifth season. Episode 22 is named "Missing" and will air on The CW next week. As viewed in the trailer, it produces one of the most expected moments for the series as Katie Cassidy returns to the Star City as the Black Siren. Read on for spoilers for this episode as well as a recap for episode 21

Highlights and plot — episode 21

In the last episode, Prometheus (J.Segarra) discovered that his father was attempting to abandon him. The destructive news led to Chase putting down his arguments and abandoning the fight. He was waiting for Oliver (S. Amell) to murder him, but the Green Arrow decided to do the best thing and secured him up instead.

He might dislike that decision in the next episode 22.

Cartermatt states,“Black Siren (K. Cassidy) returns to support Chase. Felicity (E.B. Rickards) prepares a party for Oliver birthday while Lance (P. Blackthorne) is angry after Rene (R. Gonzalez) misses the custody listening for his daughter."

The show appears engaged in apparently paying off its Rene storyline in this chapter, and our view here is that he needed the attention because of matters out of his power, it is difficult for him to be there for his daughter when he is been probably taken by someone.

Spoilers and trailer — episode 22

According to the teaser of "Arrow" Episode 22, Black Siren returns and she is here to support Chase. Also, it's Oliver's birthday and parties begin. Felicity makes the organizations for the Mayor's birthday bash, but tension arises between Rene and Lance when he discovers that Rene remained away at the custody.

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The pics published online by The CW reveal that she gets up personal and close with Laurel Lance and Quentin Lance's father. While we do not know much about Siren's entries, we do remember that she too was in love with her world's Oliver but that he departed on Earth-2 while his dad converted in the Green Arrow. We have to determine if Earth-2 Laurel's father followed Quentin and if she had the related kind of solid relationship that Lance held with his daughters.

In a conversation with TV Line, Wendy Mericle, creator of the TV Series, announced what to expect from the series finale. The final confrontation between Oliver and Prometheus won't take place in Star City and it's going to be both intense and touching.

Episode 22 of "Arrow" Season 5, will air on Wednesday, May 17 at 8.00 pm EST on The CW.