Reviewed by Phil Boothman.

After last week’s escalation, tensions are set to keep increasing in Starling City as Slade’s war against Oliver and the rest of Team Arrow continues. This week, it’s all about the technology, as we get a nice glimpse into the world of the upcoming Flash TV show and revisit a couple of things from the past.

The episode opens with the team donning slightly different costumes than usual as they break into Queen Consolidated’s Applied Sciences facility to stop Slade from using it to mass-produce the mirakuru serum. However, the only sure-fire way to do this is to blow up the entire building, and thus the team, although they get away unidentified, are branded terrorists in the news: something tells me this may come back to haunt them, but for now their troubles take a different form.

Unfortunately, that form is big, super-strong, armoured and carries a big sword: as the team returns to the Arrowcave, they find Slade waiting for them, he beats the team down almost effortlessly, then disappears, taking the ‘Skeleton Key’ (from episode 14 with the Clock King) with him. While licking their wounds and recovering from the various beatings, the team works out that Slade needs a device to help him inject the prisoners he released last episode with the mirakuru, and that the closest place with the kind of thing he would need is S.T.A.R. Labs.

The introduction of S.T.A.R. Labs, the same organisation Barry Allen works for, allows for the introduction of a couple of characters who will be appearing in the Flash pilot: namely Caitlin Snow and Cisco Ramon, scientists and friends of Barry. When we encounter them, they are cataloguing the contents of the Lab, which fortunately gives them access to a crazy weapon (belonging to man named ‘Arthur Light’, presumably a reference to the DC Comics supervillain ‘Doctor Light’) which actually manages to subdue Slade for a moment. Unfortunately, they can’t do enough to really stop Slade, and he steals a bio-transfuser which will metabolise the mirakuru serum before injecting it into the prisoners and prevent the process from killing them.

Felicity manages to track Slade down and sends Oliver after him to kill Slade while he is still weak from the blood transfusion process, but what he finds isn’t exactly ideal: while the machine is hooked up and injecting the prisoners with the mirakuru, the blood isn’t coming from Slade, it’s coming from Roy. As Oliver tries to free him, Slade and Isabel attack, and Isabel almost gets the upper hand on Oliver, until Diggle appears from the shadows and shoots her dead. Oliver manages to get away with Roy, and as they return to the Arrowcave, he reveals something which he learned on the island, and kept a secret because he was ashamed of his inability to use the information.

Naturally, what he learned on the island is revealed in the flashbacks: after the exchange of prisoners last week, Oliver and Sara are left with the decision of what to do with the one-handed, badly-wounded Ivo. Obviously both of them want to be rid of him, and as it turns out he wants a quick death as well: however, he tells them before they do the deed that there is a cure for the mirakuru, but it is still on the freighter. After he tells them this, Sara takes his gun and makes a move to give him the quick death he asked for: however, Oliver takes the gun and does it for her, telling her that taking a life will change her. Then he asks the other escapees if anyone knows how to pilot a submarine, presumably to storm the freighter again and take the cure.

So back in the present, when Diggle admonishes Oliver for not telling them about the cure earlier, to which Oliver responds that he was ashamed because he had the opportunity to cure Slade back on the island, and he chose to kill him instead. Naturally, because that murder didn’t take, everything that it happening now is because Oliver made that decision and allowed Slade to keep his superpowers. So he sends Felicity back to S.T.A.R. Labs to get to work synthesizing the cure from a single sample of mirakuru that Oliver obtained from the machine in Slade’s hideout, and we get a glimmer of hope in the otherwise unrelenting darkness that Slade is bringing down on Oliver’s life.

Elsewhere, Laurel is still reeling from the news that Slade dumped on her last week: interestingly, she doesn’t take Slade’s revelation at face value and decides to investigate his claims. After Slade’s attack on the Arrowcave, she visits Oliver and Sara at the hospital and, after seeing that her sister is covered in scars in a similar manner to Oliver, she works out that not only is Oliver the Arrow, but also that Sara is the Canary. However, after visiting Quentin in prison hospital after he received a beating from another inmate, she drops the investigation when Quentin tells her that it doesn’t matter who the Arrow is, just that he is doing the right thing. It’s actually a very similar mindset to that of Commissioner Gordon in relation to Batman, and represents the culmination of Quentin’s complete 180 on the matter of the Arrow. Then Laurel actually does something proactive and threatens to sue the DA’s office for allowing her father to be beaten, and gets him released: it was as much a surprise to me as it was to the DA, honestly.

Finally, we see Slade’s experiments paying off, as the prisoners begin to wake up after the process: and not only the prisoners, but the previously-dead Isabel, now bloody-eyed and mirakuru-powered. As if she wasn’t enough trouble already…

Verdict: 7/10

A solid episode, although one in which nothing really special occurs: after the massive change in last week’s episode, this one feels very much as though it is setting things up for the last four episodes of the season. But judging by the strength of the episode, those last four are going to be spectacular.