Slade Wilson and Oliver Queen realize that Slade’s son is dangerous in the promo for next week’s Arrow. Last night on Arrow, there were several big revelations. Almost overshadowing Oliver Queen’s story during the episode was the reveal of Vigilante’s identity, something fans have been anticipated for a year. As it turns out, Vigilante is Dinah Drake’s old partner and lover Vincent Sobel. He’s also a metahuman, with healing powers that protect him from everything – including a bullet to the forehead.

Meanwhile, Olive and Slade journeyed to rescue Slade’s son Joe from a life sentence in prison. They traveled to Kasnia to find Joe, imprisoned under the name Kane Wolfman. At first their efforts were thwarted, when Oliver was told that Kane Wolfman died in a prison fight. However, when he and Slade returned, they learned that Joe was still alive, kidnapped by a mysterious group called The Jackels who broke him out of prison. Slade went on a rampage to rescue his son, only to learn that he still didn’t know the truth: Joe was not a prisoner of The Jackels, he was leading them.

In the promo for next week’s episode – released by The CW – titled ‘Promises Kept’, Oliver and Slade learn exactly how dangerous Joe Wilson has become. The question seems to be whether he will pull Slade back into the dark side, or whether Slade will chose Oliver over his own son.

It’s interesting to note that the title of this episode is plural, meaning there are multiple promises to be kept. The most obvious one is the promise that Oliver made to his son William – the reason that John Diggle is the Green Arrow now instead of Ollie. If Oliver dies helping Slade, he will have left William an orphan. Meanwhile, he also promises to help Slade save Joe, which now looks like it might be a lost cause.

As for Slade, he has been both a friend and enemy to Ollie. He did help defeat Prometheus and save nearly everyone Oliver cared about on Lian Yu, but he will always be the man who murdered Oliver’s mother and tormented Roy Harper – and to Slade, Oliver will always have been the person who chose to save Sara Lance instead of Shado. It certainly does not seem at all outside the realm of possibility that Slade will chose his son over Oliver. If Slade does join Joe and the Jackels, that could mean even more danger and trouble for Team Arrow, who are already dealing with numerous villains this season. It also means that Oliver’s ability to keep his promise to his son is now in grave doubt.