For the most part the Marvel Knights are a somewhat rag-tag team of heroes. Lead and somewhat organized by Daredevi,l the Marvel Knights began their career by investigating the sight of a horrifically bloody massacre.
Punisher, Daredevil, Dagger, Black Widow, Shang-Chi, among other heroes filled out the groups core and all began searching for clues etc to find whomever committed the murders. Later they find out that an Asgardian troll was to blame. The troll was in the process of searching for a mystical item known as the Ragnahorn. The Knights were able to defeat the troll and retrieve the Ragnahorn putting it in the safe hands of Ulik.
Afterwards the other Marvel Knights decide to take down The Punisher. They decide that despite his aiding them in the previous fight, their strong disapproval of his lethal methods, justify attempting to take Frank Castle down. The Knights are approached by Moon Knight, a wealthy adventurer with a sordid past, who offers to finance their hunt.
Later it’s revealed that the Punisher has been sucked into a different dimension by Dagger’s former partner, Cloak who as been consuming all lawbreakers for some time. Eventually even consuming Daredevil, Black Widow, and Moon Knight while Dagger is working with Doctor Strange to try and save Cloak.
The team is plagued by bad-luck and rising tensions, they ultimately leave the Punisher alone and work with him again later on in the series. The whole story arch is just plain odd with only a few first-rate heroes taking part in any of the action. It’s a convoluted story but at the same time a good comic.