Fans of "Arrow" can expect to see more characters from the past return in Wednesday's all-new episode.

Last week, viewers were treated with a special appearance from Sara Lance, who suffered from a shocking and untimely death earlier on in Season 3. In addition, Thea and Oliver traveled back to Lian Yu in order to start training to prepare for Ra's al Ghul's attack, reports Melty.com.

This week, the hit series will bring back Cynthia Addai-Robinson as Amanda Waller, the late Tommy Merlyn and Slade "Deathstroke" Wilson. During the episode, which is aptly titled "The Return," Slade will use Oliver and Thea's arrival on Lian Yu as a means to escape the underground bunker where he has been imprisoned.

Preview photos published on Cinema Blend reveal that Thea will show no mercy when she comes face-to-face with Slade, her mother's killer. Surprisingly, it appears that Oliver will try to stop his sister from killing Slade in order to avenge their mother's death.

In the meantime, Tommy Merlyn, Oliver's deceased friend and Thea's deceased half-brother, will appear in a flashback, as Oliver and Maseo head back to Starling City in order to retrieve the Omega bio weapon.

It has also been revealed that Oliver and Maseo were brought back to Starling City by Amanda Waller in an attempt to find China White. Meanwhile, Oliver manages to successfully convey a message to his family, along with Laurel and Tommy.

According to Screen Crush, the official synopsis reads as follows:

"Malcolm (John Barrowman) puts Oliver (Stephen Amell) and Thea (Willa Holland) in a dangerous situation that lands them on Lian Yu with Oliver's former enemy, Deathstroke (guest star Manu Bennett). A flashback reveals when Oliver and Maseo (guest star Karl Yune) returned to Starling City to retrieve the Omega bio weapon, and despite being under strict orders from Amanda Waller (guest star Cynthia Addai-Robinson) not to reveal himself to anyone, Oliver looks in on his family, Laurel (Katie Cassidy) and Tommy (guest star Colin Donnell)."

"Arrow" Season 3, Episode 14, "The Return," airs on Wednesday, Feb. 18, at 8 p.m. ET on The CW.

Watch the promo video below.