When I walk into Will’s living room on Wednesday morning and see MJ sitting there, I actually grind my teeth. There’s so much I want to say to her, but I force myself to hold it in—for now, at least.

She looks just as uncomfortable as I feel.

“Uh, hey, Dara,” she says. “I just want to say I’m so sorry. I shouldn’t have made that video. I just hope you know that I never planned to show it to anyone …” She trails off, biting her lip.

“Why would you make it if you weren’t planning to show it to anyone?” I ask.

MJ plays with the strings of her COME TO THE MATH SIDE, WE HAVE π hoodie.

“Because it was a challenge,” she says. “I wanted to see if I could create a realistic deepfake with a small data set. Most people use celebrities because obviously they have much bigger data sets to use for machine learning.”

“Obviously,” I say sarcastically.

She plows on, ignoring my tone. “I was mad the night of my party, so I decided to use you and Will to experiment with some new programs that don’t require as much input. When I looked at your social media accounts, you had the most video material for me to use,” she explains, like I care about the how of this video more than the why. “That’s why it was of you accusing Will rather than the other way around.”

“Wait … is what you’re saying that if I’d had more video than Dara on social media, you’d have a deepfake of me accusing her?” Will asks. He sounds completely dumbfounded by the idea.

“Um … yeah,” MJ says, dipping her head to avoid eye contact. “But you didn’t, so I knew I’d be able to get a more realistic deepfake if it was Dara doing the talking.”

The thought that the only thing that saved me from being in Will’s place was that I’d posted a few more videos on social media sends shivers down my spine.

“So I could have been the one facing investigation by the College Board instead of Will?” I ask.

MJ nods.

A fresh wave of anger hits me. “And you couldn’t tell us any of this days ago? Like, the day Rumor Has It posted the video? That’s so messed up, MJ!”

“Dara, I know you’re pissed, but we’ve got to work together,” Will reminds me. “We’ve all got reasons to be mad—me at MJ, MJ at me, and you at both of us. But how about we focus that anger on figuring out Rumor Has It’s identity?” He looks from me to MJ, and then back to me. “They are the one we should all be mad at, because without that public post, none of this would have happened.”

“Okay, sure,” MJ says, giving me a tentative glance.

“Fine,” I say with a sigh. “But just how exactly do you propose we do that?”

“Well, the video was set to private on YouTube,” MJ says. She looks at me pleadingly. “I swear, Dara, I never meant for anyone to see it. There was no way Rumor Has It could have accessed it under normal circumstances. I think what happened is that I forgot to log out of my account in the library.”

“Why would you watch it in school if you never meant for anyone to see it?” I ask.

MJ drops her gaze to the floor. “Because Will lied to me, kept secrets. We’ve never kept secrets. We’re supposed to be best friends.”

I glance over at Will, who is wearing a pained expression. Even though I’m still angry with both of them, I feel a twinge of something. Not guilt, exactly, but responsibility. Maybe trying to keep our relationship on the down low wasn’t the best decision after all.

“And then Rumor Has It made that post saying I was upset and implying it was because I had some stupid crush on Will,” MJ continues.

“That was bad,” I say.

“It just makes me so mad when everyone acts like Will and I can’t possibly be best friends. Like, just because we’re a guy and a girl and straight,” MJ says. “And it hurt that he seemed to be ditching me because he was dating you.”

“I wasn’t ditching you!” Will protests.

“You totally were!” MJ exclaims. “I know you might not have thought that, but face it, you hardly ever wanted to hang out, and you didn’t trust me enough to tell me the real reason why. How is that not ditching me?”

“Okay, but you still haven’t answered my question about why you were watching it in the library,” I point out.

MJ bites her lip, like she’s wrestling with something. “Because I was proud of having been able to create something that realistic. It gave me confidence that I’m good at what I do, even if Carnegie Mellon didn’t want me and my best friend was lying to me.”

“If you hadn’t used Dara and me in that video, it would be much easier for me to appreciate your mad AI skills,” Will says.

“I know,” MJ says, looking up at Will. “But I swear it was just supposed to be for me, and it would have been if not for the whole Sam thing.”

“So, wait …” I say slowly, thinking aloud. “That means Sam could have seen the video. Could he be Rumor Has It?”

“Sam?” Will exclaims. “No way! He’s one of my boys. He wouldn’t do that to me.”

“That’s what you said about MJ,” I point out, with an apologetic glance at her, because I’m starting to understand that she feels pretty bad already.

“Ouch,” Will says. “But yeah, you’re right.”

“Everyone’s a suspect until they aren’t,” I say. “It could be pretty much anyone. But we have to start somewhere to try to narrow it down. Maybe with the people in the library with you that period?”

“But how do we know it wasn’t someone who came in later and found me still logged in to my account? Someone who watched it and then emailed it to Rumor Has It?” MJ asks.

“We don’t,” Will says. “But Dara’s right. We have to start somewhere, and it makes sense to start with whoever was in the library with you. If we clear all of them, then we start over and widen the net.”

“Sounds like a plan,” I say. “So, MJ, who was there besides you and Sam?”

“Ada. And Carly and Jayson,” MJ says slowly. “Carlos Ruiz … Rosa Lang … Angie Blackmon … I can’t remember who else.”

“Let’s map it,” I suggest. “That might help you remember. It worked for Will and me when we were figuring out who was where at your party.”

We sketch out a map of the media center and mark in where MJ remembers them sitting. It helps her remember a few other seniors.

“Joe Stotler … Jorge Burt … Ruthie Watson … That’s all I can remember.”

“Which computer were you using?” I ask MJ.

“I was here, and Ada was using the one there,” MJ says, pointing to their respective locations. I mark them on the map.

“Could Carly or Jayson have seen what you were watching over your shoulder from where they were sitting?” Will asks.

“I didn’t think so, but maybe?” MJ says.

“They were at your party. So were Ada and Sam,” I say. “Maybe we should make a list of everyone who was at your party and see if anyone else was in both places.”

By the time we’ve finished making and comparing the lists, there are only four people who are in the center of the Venn diagram: Ada, Sam, Carly, and Jayson.

“I can’t remember if Ada left the library before me,” MJ says. “If she did, we could rule her out. I think she did.”

“But you’re not one hundred percent sure?” Will asks.

MJ shakes her head.

“Then she stays on the suspect list,” Will says.

“So do we start with the suspects?” I ask.

“What if we ask all of those in the library that day if they remember where the others were and when they left the library?” Will asks. “See if they come up with the same answers.”

“It’s a start,” I say. “That might give us some other clues.”

“Do we know if they’re all around over break?” Will asks. “I know Sam’s around.”

“Ada is,” I tell him. “No idea about Jayson or Carly.”

“Carly left for Jamaica with her family on the twenty-second,” MJ says. “But she’s getting back in time for Amir’s New Year’s Eve party.”

“Lucky her,” I say with a sigh. I could really go for a week on a beach right about now.

“Jayson’s got a seasonal job at Lord of the Fries in the mall,” MJ continues.

“Maybe it’s good Carly is away,” I say. “If Jayson’s home, we can ask him first, then see what Carly says.”

“I’ll invite Sam and Amir over to game tomorrow,” Will says, picking up his phone to text them. “I can slip the question to Sam while he’s here. And then I can hit the mall and talk to Jayson.”

“And I’ll talk to Carly when she gets back,” MJ offers.

“Obviously I’ve got Ada,” I say.

“Good,” Will says. “We’ve got a plan. If it turns out not to be any of the people we check out first, we can divvy up the rest of the list.”

It can’t be Ada. She’s my best friend. But Will thought MJ couldn’t have, wouldn’t have made that video, and it turns out she did. It’s hard to know who I can trust right now. It’s not a great feeling.