After revealing that Ray Palmer (Brandon Routh) is still alive despite the big explosion that happened on the top floor of the Palmer Technology at the end of season 2, another unexpected twist will be unveiled in the next episode of "Arrow" season 4.

This time, the shocking truth about John Diggle's (David Ramsey) murdered brother Andy (Eugene Byrd) will be exposed.

But how will Diggle, Oliver Queen (Stephen Amell) and the rest of the Team Arrow will react to the discovery?

The trailer for the episode titled "Brotherhood" shows that Andy did not really die when he was supposedly shot by Floyd Lawton/Deadshot (Michael Rowe) under H.I.V.E.'s orders. Instead, he managed to survive the attack but was kept under the control of Damien Darhk (Neal McDonough). It is also revealed in the clip that Andy's double life as a drug lord in Afghanistan is also a lie.

Just like what Team Arrow did for Ray in the previous episode, they will also do everything that they can to rescue Andy from Darhk's claws. "Andy is under Darkh's influence and we need to take him out," Felicity Smoak (Emily Bett Rickards) says in the trailer.

But how will John process the new information about his brother? Since season 1, the former US Army Special Forces soldier has vowed to make Deadshot pay for Andy's death. Will the new information about his brother change him?

Meanwhile, Thea Queen (Willa Holland) will once again manifest the effects of being exposed to the Lazarus Pit. According to the synopsis, Oliver's sister will lose control in front of Alex Davis (Parker Young).

The rest of the synopsis reads:

"Team Green Arrow's ongoing battle with Damien Darhk is complicated by a shocking revelation. Thea's bloodlust returns and she loses control in front of Alex."

"Arrow" season 4 episode 7 airs on Wednesday, Nov. 18, on The CW.