Darker than Black is one of those rare series which is consistently better than it probably should be. It has all of the elements necessary to be a run-of-the mill series about super-powered agents, terrorists, and hoodlums, yet somehow it puts them together into two-episode stories which carry a heavier impact and sharper edge. Lurking behind all of the super-powered antics, bloody violence, and intrigue is one of the year's better series.

Though events continue to play out in two episode mini-arcs, episode 13 also marks the beginning of the series' first overarching plot. With the introduction of Evening Primrose the series now has its first recurring antagonists (although one of the bad guys from the first half of the series does also resurface and continue to be a pain in the butt for Hei) and, finally, a sense of a greater purpose to many of the events that play out, although the direction they take may be somewhat surprising and the truth about who the ultimate bad guys are may be a matter of perspective. The Evening Primrose arc also finally explains in more detail what happened at Heaven's GATE five years earlier and, with its last regular episode, explains what happened with Hei's Contractor sister Pai – and that truth should definitely be a surprise.

These episodes also flesh out the characters more. One two-episode arc gives Huang the feature treatment in much the same way that Yin got such treatment in the first half and the relationship – if you can call it that – between Misaki and November 11 sees further development; imagining those two hooking up in some doujinshi variation is hardly a stretch, and November 11, in the end, is a damn cool character. Mao, sadly, does not get the same consideration beyond the bonus episode, but Gai and Kiko continue to pop up occasionally (if typically inconsequentially) throughout. Amongst new characters, the only one of consequence in terms of development is Amber, but she single-handedly makes up for the lax treatment given the rest of the Evening Primrose members. There is something utterly disarming about that smile of hers in her younger forms and something ineffably sweet about the way she behaves towards Hei and Yin; in fact, she so completely lacks a sinister overtone that it is not hard to believe that she really does still love Hei deeply and see him as much more than just a necessary means to an end. What the price of her power is doing to her, once enough evidence has been set forth for viewers to put two and two together, is nothing short of tragic. Though technically a villainess, she is one of the better new characters introduced so far this year.

For all that the series does right in its writing, though, it does have one notable failure: the ending in episode 25 feels entirely too rushed, especially the way one major character drops out of the picture. Because of that the ending does not pack quite the impact that it should, although it does leave room for a continuation that is coming to Japanese TV this fall.

The series makes up for that with the brilliantly off-the-cuff episode 26, which was originally included only as a bonus episode on the final Japanese DVD release; it never aired on TV. It tells a side story set at some point not long after the arc involving Yin's kidnapping and with a decidedly lighter tone. Learning why Mao hates spring is a hoot, as is Yin's curious new hobby, the whole thing about attractive collarbones, and what the contents of that vial actually do, but the business with the doujinshi is truly inspired. At least one, and maybe two, lines involving it will cause almost anyone to sputter. (Drinking anything while watching this episode is not recommended.)

Studio Bones turns in some sharp action scenes and generally nice character renderings, with Amber's design at younger ages being a particular highlight. Secondary and tertiary characters suffer a bit more on the quality and refinement of their appearances, and the minor inconsistencies in artistic quality control that Bones has always been known for do show up here; in this case, they do sometimes involve less-than-stellar CG effects. Still, the series is hardly hard on the eyes.

With a score by Yoko Kanno, it isn't hard on the ears, either. The regular soundtrack for the second half is not quite as much of a stand-out as it was in the first half but still does the job well, while the shift to a new opener gives the series an energizing, seriously up-tempo rock number to get the series off to a jamming start. The new closer is less remarkable.

The key English dub role in the second half belongs to Laura Bailey as Amber, who had to effectively voice a character at multiple different ages and make her sound convincing in each case. That she pulls it off without a hitch further proves why she is one of the best in the business. Troy Baker also does a commendable job nailing down November 11's distinctive but not overly heavy Brit accent; in the volume 4 commentary track he explains his attention to detail in the way he voiced many key words. Newcomer Bucky Pearl is also exactly on the mark as Dr. Schroeder in the late episodes, as is Kent Williams as Mao, and who else Brandon Potter and Brittney Karbowski would sound right as Gai and Kiko, respectively? Other performances are adequate but less notable. The lesser amount of meddling with the original script compared to the norm for Funimation's dubs continues.

Each volume has Extras which include textless songs, an English audio commentary for one episode, and “production art” that is really more bio, location and equipment files. Volume 4's commentary is for episode 16 and features Troy Baker and Laura Bailey. Volume 5's commentary is for episode 22 and features production staff, while the episode 26 commentary in volume 6 (a curious choice!) features Kent Williams and production staff.

Although it has an occasional light-hearted moment and does parody otaku with its Kiko character, Darker than Black is generally a serious and mature tale about super-powered agents playing deadly games with each other while trying to retain some semblance of personal identity. It is sexy with its occasional fan service (one Contractor introduced in these episodes can teleport, but her clothes do not travel with her), offers no shortage of action or violence, and save for a rushed ending typically delivers solid writing. It is not the year's best series, but should be a contender to be ranked amongst the better ones.