I won't spoil the story in this review, but this is one of the best Warhammer 40K Adventures to come out in the last few years.
The Hand of Corruption is not all about combat, but it draws from adventures in the Dark Heresy by making players utilize a variety of skills and talents. Of course, there is combat, but it is balanced with using skills, working as a group, and problem solving. I like that the writers kept in mind that just because people play Chaos characters doesn't mean they hate to use their brains instead of their swords.
This adventure is challenging, but not overly so. I ran this adventure as the GM with a group of three (1 Chaos Space Marine, and 2 Humans). They would be considered lower level in other games (as Black Crusade doesn't have levels per se) and there were a few tense moments, but the players were able to make it through the adventure and had a lot of fun.
In fact, running the Hand of Corruption was one of the most fun that I have had running a game in a couple of years.
I highly recommend this adventure and the Black Crusade!