"Guardians of the Galaxy" was easily the breakout hit of the Marvel Cinematic Universe's Phase Two. Now, Star-Lord and his merry band of intergalactic miscreants are back for another adventure.

Here's everything you need to know before seeing the latest addition to the MCU, including what the team's new mission is and why you should absolutely stick around after the credits.

1. The Team Gets Some New MembersAll five of the original Guardians return for "Vol. 2," including Star-Lord (Chris Pratt), Gamora (Zoe Saldana), Drax (Dave Bautista) Rocket Raccoon (Bradley Cooper), and Groot (Vin Diesel). But the team will expand a little for this next adventure.

Yondu (Michael Rooker) will be more ally than frenemy this time around, while Nebula (Karen Gillan) is apparently abandoning her father, Thanos, and throwing her lot in with the Guardians -- but not before clashing with sis, Gamora. (Nebula will not officially join forces with this "bunch of a-holes," and fans can expect her to go out on her own by the time the movie ends.)

Fans will also see one entirely new character seemingly join the roster. Mantis (Pom Klementieff) is an empath/psychic who just might give Drax a run for his money as the most socially-awkward member of the team.

2. There Will Be Lots of Baby GrootWhen last we saw the Guardians, Groot had narrowly survived his great sacrifice and was slowly regrowing his body. It doesn't appear that he's made much progress since then.

Groot may be mobile again in "Guardians of the Galaxy Vol. 2," but he's still a far cry from the giant tree monster he used to be. But that's okay, because all signs point to Baby Groot being the sequel's breakout character. The trailers alone make it clear that Groot is responsible for more comedy than ever, and based on the amount of Baby Groot-themed merchandise out there, Marvel clearly expects fans to fall in love with this tiny, squeaky-voiced incarnation of the character.

3. Say Hello to Star-Lord's DadThe first "Guardians" played up the mystery who Star-Lord's papa was; all we knew at the time is that it was some cosmic being powerful enough to make Peter Quill capable of wielding an Infinity Stone without vaporizing himself.

That mystery gets solved in "Vol. 2," as the team comes face to face with Star-Lord's pops, Ego the Living Planet (Kurt Russell). What the heck is a Living Planet, and why does it look an awful lot like Snake Plissken? You'll just have to watch the movie to find out. (And don't expect Ego to be a straight-up good guy. As family reunions ago, it's not one of the best.)

4. Thanos Sits This One OutThe first "Guardians" was notable, among other things, for giving Thanos his first significant role in the MCU. But even with Marvel Studios steering full-steam ahead to 2018's "Avengers: Infinity War," don't expect the Infinity Gem-coveting villain to make a return appearance here. A few characters mention the owner of the best space chair ever by name, but the movie never shows him. Or his chair. Instead, it looks like High Priestess Ayesha (Elizabeth Debicki) and her people, "The Sovereign," will serve as villains this time around. The Sovereign are a race of intensely xenophobic aliens who become the latest in a long line of enemies Star-Lord manages to attract. It's kind of his specialty.

5. The Cosmic-side of the MCU Expands Director James Gunn is making a point of keeping Star-Lord the only (mostly) human character in this film. Instead, the goal is to offer moviegoers an even wider glimpse of Marvel's cosmic characters.

That means new alien races like the Sovereign, new beings like Ego, and plenty of other surprises along the way. Expect even more nerd-friendly cameos and Easter eggs this time around, including the debut of a new MCU character played by a certain Italian Stallion.

6. Stick Around for the End Credits
Marvel fans are conditioned by now to stick around when the credits roll. And that's a good thing, because "Guardians 2" has plenty to offer diligent audience members.

The first film featured two end-credits tags -- Baby Groot dancing FTW! Its sequel sets a record for the MCU, with five (!) -- one of which features our pal, Stan Lee. But none of the scenes set up or tease "Infinity War," at least not directly.

Find out what all five scenes have in store when "Guardians" hits theaters Friday.