Black Siren (Katie Cassidy) caused chaos as she murdered seemingly unimportant people on the latest episode of Arrow.
It was revealed that she was working with Cayden James (Michael Emerson), who Felicity (Emily Bett Rickards) worked with Helix to break out of ARGUS. Alena (Kacey Rohl) asked Felicity to help stop Cayden’s planned attack that would result in millions of casualties.
Oliver (Stephen Amell) kept interfering, which angered Felicity, but Team Arrow saved her life when she was almost shot. Alena was wounded but survived.
Felicity figured out that Black Siren was killing her victims to steal their fingerprints to enter the International Domain Name Directory (IDND). She managed to stop Cayden’s planned attack but she was unaware it was all part of Cayden’s plan so he could cover his tracks.
Elsewhere Felicity recruited Alena for her start-up and Black Siren was given a device to stop Curtis (Echo Kellum) tracking her. At the end of the episode Oliver received a call from Slade (Manu Bennett) asking for his help.
The next episode of the season is Deathstroke Returns. Slade gets Oliver to help him track down his kidnapped son, until a terrible revelation shatters all hopes of Slade ever seeing him again.
Tune in to Sky 1 HD at 8pm on Thursday to see the episode. Preview it with our gallery below: