'Arrow' Recap With Spoilers: "Promises Kept"

"Promises Kept" picks up immediately where last week's episode ended, with Slade's son — Joe Wilson — holding his father and Oliver at gunpoint. After talking to him a while, Joe puts the gun down and tells his father they have some catching up to do and the two leave the scene.

We see a flashback seven y ears ago where Slade is in an A.S.I.S. medical facility. He's bedridden and gauze is covering his eye. Joe shows up to visit and because Slade's suffering from amnesia, fills his dad in on how he got where he is.

Present time, Team Arrow is staking out a group of bad guys at a warehouse. When one of them throws a smoke grenade, the team's force to fall back.

Back at Arrow HQ, Felicity reveals the group of thieves were after a military-grade 3D printer. They'd be able to use it to print weapons, drones, or a variety of other harmful objects.

Diggle turns away from the group and looks down at his hand — it's shaking.

Slade and Joe are talking over some whiskey.

Diggle goes back home and talks with Lyla, who knows her husband has now taken up the Green Arrow mantle. After delaying her advances for some adult "happy fun time," Diggle pulls out the same drug gun we saw him use last week.

Elsewhere, Slade's talking to some of his son's colleagues when Oliver steps out of the shadows. Slade warns him to go home, but Oliver insists that he stay.

Joe walks in and gives the crew their next mission. He turns to his father and asks for his help. Slade obliges and says he has to go back up some grew. We reveal that Slade has set up a communication system to stay in touch with Oliver.

We see another flashback to Slade in the A.S.I.S. facility — he's training in hand-to-hand combat with Joe. Joe ends the training session and Slade begins having hallucinations of Shadow, his former associate.

Back in present day Star City, Diggle is drug production facility talking to a gentleman by the name of Ricardo Diaz. Diaz makes it clear his company doesn't have FDA approval and orders one of his lackey's to "load" Diggle up with more of their product.

In Kasnia, Joe's crewy is working on their heist of weaponry from the Kasnia army. They pop the tires of one of the army transports and kill all of the soldiers in the vehicle.

We see Oliver sneaking around close by when he's nearly caught by a few lookouts. He's able to take care of them and uncovers a receiver that Joe's crew is using for some centex explosives.

Rene brings a stack of pizzas to Arrow HQ but they're unable to enjoy them, Felicity has the whereabouts to the thieves trying to still the souped up 3D printer. A shootout begins and one of the thieves steps out of one of the vehicles — it's Diaz. Diggle freezes and is shot in his armor. The thieves get away.

Back at HQ, Felicity's briefing the rest of Team Arrow on Diaz — with none of them knowing Diggle's connection to the apparent crime kingpin.

In Kasnia, Slade approaches Joe about the reason for all of the explosives and Joe counters by saying that none of his men trust having his father around. Joe tells his dad that he has a present for him and one of Joe's henchmen bring in Oliver. To not blow his cover, Slade punches Oliver.

Another flashback to the A.S.I.S. facility and Slade is still having hallucinations of Shadow. The tv playing in the background has a news report of Oliver being found by fishermen.

Diggle approaches Lyla about the tremor he's been having. He informs her that he's been taking experimental steroids and asks if ARGUS is working on anything that could help him. He then tells her that he's been purchasing the illegal drugs from Diaz. She walks off telling him she wants to be alone.

Oliver is tied to a chair. Slade has a sword to his face — Joe has persuaded him to take an eye for an eye. Slade walks behind Oliver and uses the sword to cut Oliver's restraints. Oliver knocks Joe out and joins Slade with taking out the rest of Joe's henchmen. Slade and Oliver are able to escape the facility. Looking out of the building, Joe awakes and mentions that he's going to kill his father.

Oliver tells Slade he was able to find out that Joe and his cronies are going after Kasnia's water supply. Slade expresses regret about helping Oliver out, saying he'd do anything to stay with Joe. Slade says he thinks the only way to stop Joe is to kill him.

In the flashback at the A.S.I.S. facility, Slade has killed everyone there. Joe goes to stop him on his way out, but Slade knocks him out.

Curtis and Felicity have found the location of Diaz again and Diggle orders to suit up, they're going to go take him down. Team Arrow converges on Diaz' location and he orders his team to take all of the product, making sure nothing gets confiscated.

Diaz tips over a cannister of gas and lights it on fire, destroying the stock of drugs he had made.

Oliver and Slade approach Joe's group. While Oliver's taking care of the henchmen outside, Slade and Joe start fighting with their choice weapons — swords. Joe reveals to Slade that he has a brother named Grant, a secret that his mother had kept. The news is something that distracts Slade and Joe's able to knock Slade off his feet.

About the deliver the final blow, Oliver's able to shoot the sword out of Joe's hand and Joe throws a grenade to distract Oliver and Slade, allowing him to escape.

Slade convinces Oliver to go home while he stays abroad to continue looking for both of his sons — Joe and Grant.

In Star City, Diggle comes home to Lyla, and she tells him she heard Team Arrow destroyed Diaz' drug facility. Diggle says that he planned to take of the drugs out of the warehouse and apologizes to Lyla for taking them.

Felicity and William are playing Mortal Kombat when Oliver returns home. Williams fills his dad in what he all accomplished when he was away. Williams runs off to find a science project and Oliver fills in Felicity on the mission with Slade.

Diggle assembles Team Arrow at the bunker and informs them about his tremors and subsequent drug usage. Curtis offers to help him get better. Diggle tells Dinah that he promises to keep no more secrets from her and as she turns away, Dinah looks down at the present her ex-boyfriend gave her last episode.