The next evening, Ladybug leaps onto a rooftop, and Flash stands in front of her, as he runs up.

(WHOOSH!)

Ladybug: What's up, Flash?

Flash has a stern look on his face.

Flash: When were you going to tell me, Ladybug?

Ladybug is confused as to what is going on, and by Flash's sudden change in demeanor.

Ladybug: Tell you what? What's gotten into you, Flash?

Flash: You know exactly what I'm talking about. You abused your powers to humiliate Lila, and keep her away from Adrien!

A look of realization dawns on Ladybug.

Ladybug: Where did you hear that?!

Flash: Where do you think? Lila told me what happened, she said you ruined her life.

Ladybug soon becomes annoyed with Flash.

Ladybug: You shouldn't believe a thing Lila says!

Flash: I know, so I asked Adrien for his side of the story, and it was the same as Lila's. Only, he wanted to know why you decided to do that to begin with.

Ladybug gets aggravated by Flash's statement.

Ladybug: I don't put up with lies, especially if they're about me! If all you wanted to do was waste my time, by telling me that, then I'm leaving!

She starts to walk off.

Flash: So it's bad if somebody tells lies about you.
But it's okay, for you to lie to everyone else. Right, Marinette?

Ladybug stops in her tracks, she turns back to Flash, with a shocked look on her face.

Ladybug: W-w-what did you say?!

Flash: That's right, I know who you are, Marinette Dupain-Cheng!

Ladybug starts to sweat.

Ladybug: You're wrong, I-I'm not Marinette!

Flash: Now who's the liar?
I have the evidence, right here.

He holds up the little vial of Marinette's blood.

Ladybug's eyes grow wide with panic, but she tries to remain calm.

Ladybug: W-What's that supposed to be?

Flash: This is a blood sample I took from you, the day after we defeated Archaeologist.

A flashback show Marinette's nose is gushing blood, and Barry takes a sample of blood when she wasn't looking.

Flash: "I ran a test on the sample, against one I found under the Eiffel Tower. After our first clash with one another."

Ladybug gets punched in the nose. Then later, Flash swabs a blood splatter on the concrete, under the Eiffel Tower.

Barry scans both samples, which appear identical to each other.

The flashback ends with Flash staring coldly at Ladybug.

Flash: And when the results came back, I discovered that the blood samples, were an exact match. So, you still want to stand there and lie to my face?

Ladybug, still in a state of shock, de-transforms.

Ladybug: Spots off.

A flash of pink light washes over her, and she turns back into Marinette.

Flash: I just want to know why. Why did you do it, Marinette?

Marinette: Listen, Flash. You don't know what she did to try and ruin my life.

Flash: You'd be surprised.

Marinette: Did she tell you she tried to get me expelled from school, by saying that I stole from her, and lying about pushing her down the stairs?

Flash: Yes, she told me about everything she did. And the only reason she did any of that, to begin with. Was because you let your jealousy get the better of you! You've got to realize that Adrien isn't an object to possess, he's a human being. And you can't decide who dates him.

Marinette: I, uh-

She hangs her head in embarrassment.

Flash: How many times are you going to let your jealousy and impulsions cloud your judgment? You're better than this, Marinette. I've seen that, firsthand.

Marinette: You're right, Flash. I just can't help it, I love Adrien so much. But I don't know how to get him see that.

Flash: (Sigh) Look, I know your heart's in the right place. And you're just trying do the right thing. But there's other ways of solving a conflict without humiliating someone.

Marinette: All right, Flash.
I'll try and work on keeping my impulses under control.

He nods and begins to walk away.

Marinette: Wait, do you know who Cat Noir is, too?

He turns back to face her.

Flash: Yes, but not to worry. I'm not spilling the beans.
I know Master Fu would revoke you and Cat Noir of your Miraculous, otherwise.

Marinette is surprised.

Marinette: You know Master Fu?

Flash: Well, I'm sure I can find him. I mean, how many people can fit the description of an old man in Paris by the name Fu?

Marinette: A fair point. I mean, it's not technically breaking the rules if you found out yourself, right?

Flash: I guess not.

Marinette checks her phone.

Marinette: I've got somewhere to be, do you mind, uh-?

Flash: Sure, no problem.

He picks up Marinette, and rushes her to her destination.