Jericho's secret is taken directly from the comics.
Season Six: Burning Bright
Episode Five: The Devil You Know
Raven was the first of the Titans to find vital information, but it wasn't at all the story that she had expected.
Jericho had agreed to come to the Tower to speak with her about Slade. The pair of them sat on the roof for the talk, and it was hard to say just which of them was more uncomfortable. Jericho knew what the conversation was going to be about, and Raven knew her interpersonal skills still needed work to put it lightly. There was no chance that she would be able to be sympathetic and kind-hearted about it the way that Starfire could manage, or turn it into an easy talk like Beast Boy might be able to do. She settled for a blunt approach coupled with a tentatively deliberate use of empathy. Instead of passively hearing what the world was feeling, she'd try to be sure about what Jericho felt.
"You know something about Slade," Raven began quietly. Starfire had taught her that serious conversations were easier in quieter tones, and that it made the voice sound gentler. "If I can let it stay between us, I will, but right now all of want to stop Slade. We don't want him dead by any means, but he is a threat to everyone."
Beast Boy, Jericho typed into his communicator.
Raven nodded curtly. She had wanted to avoid that subject, but that hardly was fair when she was asking about something that Jericho had kept so personal. "Luckily, that didn't end the way Slade predicted. We think Slade was trying to use Beast Boy to hurt Robin." Raven couldn't suppress a frown at the thought of what that might have done to their team. "We're concerned that Cyborg or Starfire will be next. Slade's branching out."
Jericho was the one to frown after those words. He's gone after you. It wasn't a question.
Raven had expected that to come up eventually, but hadn't thought that the topic would arise so soon. "Yes. He did. I… it's hard to discuss without the particulars. After our last fight with Terra, we had strong reason to believe that Slade was dead. He was, but he made a deal with Trigon."
Jericho's bright green eyes widened. Raven didn't think he realized that he was shaking his head in denial.
"I know because…" The words were hard. Raven didn't let herself look away from her teammate. "Trigon is my father. My mother was human, but that doesn't change what I am."
Jericho stared at her intently. Raven had the feeling that he was making some kind of judgment, even before he made the decision to slowly type out his next sentence. Somehow, Raven had passed.
Slade is mine. My father, that is. He's also part of the reason I can't talk anymore. Jericho unwound his scarf to reveal a thin white scarf across his throat. It's a long story.
Raven didn't ask just what that story was. She confined herself to wondering how both of them could be so calm, but she supposed there wasn't any other choice. They could be upset about their fathers for years, or they could accept it and try to be the better person. It wasn't in either of their natures to spend forever hoping that the past could change.
In the face of such calm, Raven could be sure about her own emotions. She wasn't acting because of his impulses and feelings, she was acting on her own. "I'm sorry we have that in common, but it's good to know that I'm not the only one that's had to stand against a father. Mine wanted to take over the world."
And mine wants to hurt all of you. I don't know if I'll directly stand against him yet, but I'll tell you what I know.
Neither of them made a move to immediately clarify just what it was that Jericho knew. They both sat back in the sunshine, and they both had the quiet relief of knowing that they weren't alone. Later, when Jericho took up his communicator, Raven was ready to learn all that she could.
While Raven and Jericho were on the roof, Cyborg was in his lab muttering very impolite things about Jericho's father. Slade hadn't replicated the original toxin that had prompted Beast Boy's transformation. He'd created a purified version of that toxin with adrenaline as well as a severe muscle irritant to exaggerate the effects of the strange green chemical that didn't resemble any sort of compound he could find in research or development.
By the time Robin came to check on his progress, Cyborg had the answer. "I've found somebody buying several of the pieces that went into the toxin. Slade has a pseudonym, Rob, or maybe Wilson is really has last name. No way of telling him. I know where he got the components." Cyborg had found a trace. He'd leave the details up to Robin. "I still don't know how he was so sure that they would send Beast Boy straight into were-beast."
"It's still good work, Cyborg." Since the Brotherhood of Evil, Robin had been freer with casual praise not directed toward Starfire. "I don't think we need to worry too much about Beast Boy after what happened. He'll fight for us no matter what form he's in."
"Unless Slade finds a way to change the mix of this. I'm worried about whatever this is." Cyborg tapped the monitor to show a computer-generated look at a strange protein with four separate unnatural components that no science on record had seen. "Slade's too good at what he does with toxins and nanobots. I haven't found any proof, but I think there might have been more nanotechnology to deliver the drug more effectively. I was working on traces of the toxin to start and might have mixed the mini-robotics he likes."
Robin scowled at the created enzyme on the screen. "Are you going to let him know?"
"Might let Raven handle it. She and BB are pretty close, lately, and he'd take about anything easier if she said it." It was past time that Cyborg was able to talk to someone about what he saw. Starfire could keep secrets, but it wasn't fair to ask her not to help two people be happy. As much as she'd like to help, however, some things jut took time. "They're both too shy to admit to anything just yet, but I know that you'll leave well enough alone."
"Starfire might not." Robin knew just what Cyborg had been thinking. "It will sound better coming from Raven anyway. She has the best idea about what it's like to lose control for something that isn't her fault."
"Besides that, I want Raven to know just what's happening. She has the best chance of getting Beast Boy back to us if Slade ups the dose on whatever this is that guaranteed Beast Boy would end up angry about everything." Cyborg changed settings to let the molecule rotate again. "Best as I can tell, this hooks up to everything alpha and beta in the sympathetic nervous system. Something about it might not let fleeing be an option."
"Fight or flight, for the sympathetics?" Robin asked. When Cyborg nodded, Robin shook his head. "This isn't any kind of good. Slade's too far ahead of us. Sometimes it feels like he knows more about how our team works than we do."
"There's a difference this time. We're not waiting for him to work against us. As far as I'm concerned, I should be okay. I added in a few shutdown protocols in case he figured out how to turn me against you. As soon as any of you come in my sights, everything but baseline goes offline." Cyborg changed the display to show a new model of communicator. "This one's for the main group only. There's a new voice-activated setting that should respond to any of you when any communicator's in-range. I trust you all to use this if I'm about to hurt somebody."
It was a heavy responsibility. Robin agreed without hesitation. "He's tried to do use us against each other before. It's a good thought, and you know that we won't want it to come to that."
"Mostly, I'm worried about Star." Cyborg shut the monitor down to avoid the pained look on Robin's face. Cyborg wasn't going to pressure his leader even if he did think that Robin was being moronic. Distance wasn't helping Starfire. More happiness would only make her more effective in the field. "Slade's too good at manipulating people."
"We'll watch her back." Robin's voice was rough. "We'll watch everybody's backs. If we're not careful about staying together, Slade will rip all of us apart."
Far above Jump City, the Titan under discussion was peering down at the tiny people below her. "I am amazed that you are able to see so much, friend Beast Boy." The green golden eagle flying nearby made a sound of agreement. "I am unsure what it is that we are meant to find, however. There is far too much motion in the district of warehouses at this time."
The golden eagle shifted into a parrot that flapped its way to Star's extended hand. "I'm not finding anything," the green scarlet macaw said. "The problem is that I don't have any flying form that sees well from this high up. I'd have to get closer at night. Even now, I'd see better if we made a few low sweeps."
"I will consult friend Robin," Starfire said, carefully tucking Beast Boy against her side so that she could tap the buttons on the communicator she held in her other hand. "Robin, this is Starfire. We desire to move in closer for a more optimal view."
"Go ahead, Starfire. Raven is still talking to Jericho, but Cyborg and I will be out to join you shortly," Robin replied promptly. "We'll all compare notes later."
"Duly noted, fearless leader!" Starfire chirped, mostly for the way that it would make Robin blush. She could tell from the communicator's screen that she was not disappointed. There were many advantages to listening to the constant banter between Cyborg and Beast Boy. "We shall endeavor also to question workers that appear friendly about any unusual activity."
"Great idea, Starfire." Robin looked to his left, presumably to better see Cyborg. "Expect us in fifteen minutes if traffic is as bad as we're predicting."
"Done," Beast Boy said before his macaw form shifted smoothly back into a golden eagle. He fell from Starfire's arms for several yards before unfurling his wings and swooping into a wide arc over the target that Robin had chosen as the most likely.
Starfire smiled at Beast Boy's exuberant flight. It always pleased her to know that someone else found flight so exhilarating. Raven had grown much braver in her emotions of late, Starfire knew, and it seemed that Raven might yet learn how to truly express her enjoyment. Starfire's thoughts grew less distracted as she descended to the level of the warehouse, just in time to notice Beast Boy in the form of a green sparrow perched above an open warehouse door. "Friend Beast Boy?"
He landed on the ground in a crouch after changing from sparrow to human in midair. "Something isn't right, Starfire. I think we should wait to investigate until the rest of the Titans get here."
"Too late, crudbrains," said a voice that Beast Boy should have expected. When he turned, Gizmo had a tranquilizer gun aimed straight at him with a too-familiar green liquid visible with human eyes from twenty feet away.
Starfire winced when she heard the sound of a gun, but Gizmo had not fired. The darts hit Beast Boy's unprotected back while he had been staring at the one-time HIVE operative. "Robin," Starfire said into her communicator before any of the expected transformation could begin. Her leader had to know the urgency of the situation. "We are at the warehouse you suspected, and—"
That was all Starfire had time to say before her communicator's screen changed to blue. The communicator itself was not responsive. She had time to remember Cyborg's comments about a pulse of electromagnetism before she realized that Beast Boy was not changing, and that he was not on his feet. The darts in his back had been green, but the only effect had been to leave Beast Boy crumpled on the ground of the alley.
"Friend Beast Boy!"
"I don't believe he can hear you, Starfire," Slade said from the shadows.