So, you’ve finally decided to dive into Stay Close, the British thriller that tells the story of three people who are haunted by a mysterious disappearance that rocked their small town nearly two decades earlier. (And if you haven’t seen the premiere, you might want to do that now, unless you don’t care about spoilers). At the end of the premiere, we learn that, even though everyone has attempted to move on, a new case — featuring another vanished young man — threatens to turn everything upside-down. The credits roll. You could be thinking, “Great, let’s blast off into Episode 2.” But let’s be honest — you’re probably actually thinking, “I’m sorry, what the hell just happened?”

Admittedly, there’s a lot to take in during the first hour. These characters have so much history, and, unless you’ve read the book it’s adapted from, you’ll probably spend a lot of time trying to figure out, well, everything. The good news is that it gets easier to follow as the show goes on (this isn’t The Witcher), but we figure a little cheat sheet wouldn’t hurt to make the ride easier. Here’s what you need to know after watching the premiere.

How did Cassie become Megan?

Megan (Cush Jumbo) initially seems like a picture-perfect mom and bride-to-be… until she gets home from her bachelorette party to discover a letter, addressed to Cassie, waiting for her.

It turns out Megan was known as Cassie when she was younger. At the time, she danced at the club, Vipers, and became entangled with the abusive Stewart Green (Rod Hunt). A particularly violent encounter with Stewart caused Cassie to abandon her entire old life and change her name to Megan. Oh, and for some reason we don’t know yet, Stewart’s been missing for 17 years. 

Unfortunately for Megan, her new life is threatened when a friend from her Vipers past, Lorraine (Sarah Parish), comes looking for her.

Who is Carlton?

The series opens up with a drunk stumbling out of a club. He runs into the woods, where it seems like he encounters someone else.

We later learn that the drunk’s name is Carlton Flynn (Connor Calland) and that he disappeared that night. His disappearance has drawn in local detectives and draws parallels to Stewart, who also went MIA in the same place Carlton did… 17 years to the date.

An added complication? Megan’s daughter was with Carlton the night he disappeared. (Why? Good question!)

Can Ray be trusted? 

At first, Ray (Richard Armitage) seems to be a down-on-his-luck photographer, stuck dealing with bratty rich kids to make a living. But, by chance, he snaps whatever happens to Carlton in the woods, right before his disappearance. Furthermore, flashbacks reveal that Ray was Megan’s fiancé back when she was dancing as Cassie… and was the man she left behind when she bolted after whatever went down with Stewart. 

How far will Detective Michael Broome go to get closure?

Detective Broome (James Nesbitt) worked Green’s case and clearly has not let it go (aka your standard TV cop). But when Carlton goes missing, he very quickly makes the leap to tie the two disappearances together, using pretty flimsy evidence. (Basically the location and approximate missing date; he only discovers later they vanished on the same day 17 years apart.)

But that’s not the only complication in Broome’s life: His detective partner is Erin Cartwright (Jo Joyner), his former wife, who didn’t think he was the right person to have a family with. Can he really be objective if the case has taken over his life?

Now that you have more of a sense of who’s who and what’s what, it’s time to strap in and enjoy the mystery that’s about to unfold. With twists and turns in every episode, Stay Close is compelling, can’t-miss storytelling — even if you still need to keep your cheat sheet close by.