Darker than BLACK: 6-10 (re-watched)
If episode six and what came before are examples of the series strong points, the opposite is true of 7-8. The preview music, changed from a slightly depressing tune to one more fitting for comedy suggested the two episode story would be a change for the worse, and indeed it was.
Comedy has no place in a series titled Darker than BLACK. Comedy has no place in a series that, up until that point, had been deadly serious, including lots of death and no happy endings. So, when episode seven introduced a comical detetive and his 'sexually harassed', pink haired, anime loving assistant, it didn't fit. Even the two stories featured in these episodes, both being about - I kid you not - body odur, barely connected, if they did at all.
The introduction of the filler detective is the start of the downward spiral for this series.
Episode 9-10 did return to being more serious, but even that story had more light-hearted moments than the first six episodes. It was as if the writers tried too hard to connect Misaki to the story, ending up linking her to the Chinese mafia through her friend, who has a bee sting addiction. (Whenever something is wrong with manga/anime, the Chinese and/or Chinese costumes are to blame. Always.) The episodes were saved by some decent Misaki character development, the villain having an awesome power involving his own blood and Hei smashing through a window at the end. Not on the same level as the opening episodes, though.