The Defenders Netflix series is a culmination of four distinct shows, one of which has two full seasons. With that being the case, you're probably looking desperately for a Jessica Jones summary, or one for any of the Marvel shows to refresh your memory on where exactly things left off. After all, a lot has happened, but there are a number of unifying elements across the different series that, not surprisingly, come back in a big way in The Defenders.
The Hand pops up in Daredevil and Iron Fist, Luke Cage has a few different romances in a couple different series, and Claire Temple appears in all of the characters' standalone shows. So you don't need just a Jessica Jones or Luke Cage summary, but a complete Netflix Marvel shows recap.
Here's everything you need to know to center your qi and get you ready for The Defenders. Warning: there are spoilers for each individual Marvel show on Netflix. Do your best Matt Murdock impression if you haven't watched them yet.
Season 1 of Daredevil revolves around Matt Murdock's efforts to take down crime-lord Wilson Fisk, AKA Kingpin. However, halfway through the season, there is something of a one-off episode in which Matt's old master, Stick, emerges, enlisting Matt's help to take out a weapon called the Black Sky. It turns out the Black Sky is a kid in chains who Stick murders, causing Matt to freak the F out. At this point, we don't know much about the Black Sky except that it's some sort of mystical human weapon that the Japanese crime syndicate is after, and more than one can exist.
One of Wilson Fisk's crime associates is an old lady named Madame Gao who has a vaguely mystical sense about her, although it's some time before we get to see the true extent of her nature. She has her hands in many illegal pots, including a heroin operation that Matt shuts down in Season 2.
Daredevil Season 2 splits its time between the storyline of the Punisher, AKA Frank Castle, and Daredevil dealing with The Hand. Although Jon Bernthal's portrayal of Castle is stunning, mesmerizing, unbelievable, he's not in The Defenders, so he's not relevant. The Hand, however, is, and we learn that they're an ancient organization, the organization, that is seeking the Black Sky to further their dastardly ambitions. It is revealed that they have the ability to bring people back from the dead using their dark arts.
Madame Gao pops up again in Iron Fist, running shady deals out of the Rand Enterprises building. Danny explains to everyone all the time that The Hand's goal is to break into K'un-Lun, and his role as Iron Fist is to stop them. A little confusingly, Madame Gao is imprisoned by a different faction of The Hand, but there's never really an explanation for it. Regardless, we begin to see that there's a little more to Gao than meets the eye - she has some kind of mystic power.