Restoration

"I want you to bring my sister back to life."

- Laurel demanding Malcolm bring ressurect Sara

"Restoration" is the third episode of the fourth season of Arrow, and the seventy-second episode overall.

Synopsis
The growing tension between Oliver and Diggle puts both their lives at risk when they go after Damien Darhk and a H.I.V.E. deployed meta-human. Meanwhile, Laurel talks Thea into returning to Nanda Parbat to ask her father to put Sara into the Lazarus Pit. However, Laurel is surprised when Nyssa refuses to do it.

Trivia

 * This is the second episode of Arrow to have a Meta-Human as the main villain the first being "Broken Arrow"
 * When Curtis is showing Felicity his technology, he shows her what appears to be a metal sphere. In the comics, Michael Holt, known as "Mr. Terrific" uses artificial intelligence called "T-Spheres", similar in appearance to the prototype seen.

Production
Preperation ran from July 24 until August 4, 2015. Shooting began August 5, 2015 and ran until August 17, 2015.