Raph was sitting by the kitchen, doing dishes quietly as he hummed a little tune, the sound of the clock ticking in the background was giving quite a good feel to the song, once Raphie finished washing the dishes, Leo walked in with a few plates and cups, probably from his room, and placed them by the sink, Raph's urge to shove his foot up Leo's ass would've won in an instant if he didn't glanced over to the clock and seeing how late it was already, Donnie was gone for about 6 hours now and he began worrying about his little nerd bro, Leo soon noticed his big brother's concern and tried to give him some words of affirmation, just to be shoved out of the way when Raph went over to his own room to fetch his phone so he can call Donatello.
During this time, Michael is going through Donnie's tech, investigating the weird gadgets and gear he had, Donnie's cellphone rings, Raphael is calling, the nickname given to the oldest brother was "Brawns", in fact, Michael was only able to fully tell it was Raph calling because of the picture attached to the profile, but then he realized he could use the call to his advantage, he gets the voice recorder and prepares to put on a show, he picks up the call.
🔴 - "Hello?! Donnie? Where are you? Where have you been? Are you ok? It's late, are you getting home already?"
Mikey gives a muffled little giggle before doing his little experiment, with a click of a button, the sound of a sharp and painful scream blasted through the microphone, reaching Raphael like a thin arrow, he calls out to his little brother, but all he gets is the nerve wrecking noise of sheer fear and despair in Donatello's, the screaming, the pleading, the begging, the screaching, they didn't last more than 3 minutes, but it felt like an eternity, once it was over, Michael quietly hung up the phone and broke the device in half just for good measure, the feeling of anguish and terror infested Raph's mind as it began picturing all of the worst scenarios of what could be happening to his brother, he couldn't even bare to think about the horrors he must be going through.
Meanwhile, in the other end of the call, Michael burst out laughing, imagining how the big red must be freaking out right now, his conscience tries to guilt him for doing what he's doing but Michael is just too caught up onto his own malicious schemes of revenge, he was all inside his own head, ignoring logic in favor of his pride and grief, they took him away from his father and them took Draxum away from him, and now he's gone for good, leaving Michael with the whatever remained from his stay in this life, he feels broken and like a part of him was ripped out and is now missing, his anger is taking the better of him, and without his father's comfort and guidance, he's got no moral compass to put him in the right path and his uncles are not very authoritarian, so they don't really have any influence or control over him and his actions, also because they know very well how unstable he can get when furious and getting on his way is basically life threat.
They remember that once when he was younger, he was losing a fight in the Battle Nexus and they tried to step in, but he was so feral in that moment that he just set himself on fire and screamed out a roar of rage, nearly burning them alive and hurting their little ears, and that was a second before he lauched himself at the enemy and literally put the poor soul through a massively thick wall with a single headbutt in the enemy's stomach, and that episode taught them something, that if Michael ever goes truly unhinged, the best thing to do is run for your life, for his anger issues are his and his dad to handle, after witnessing how mindless he becomes in the face of anger, they never left his anger issues get out of hand, always making sure to calm him down in moments of pain to make sure he keeps his feet on the ground instead of being carried away by violent impulses.
Besides, they don't even know what he's up to, Michael went out of his way to hide all of that from them, he's keeping Donnie trapped in their basement, away from their sight and reach, and the walls are pretty thick so it's hard for the sound to go through, Huginn and Muginn are already pretty busy with the searching for Baron Draxum, so the two are spending quite a while away from home, and Michael has been figuring outwhat to do with his time alone, he doesn't allow himself to believe that they will find his dad, he has been hurt so many times now that he just finds it hard to get excited and faithful about reuniting with his father.
Back in the turtle's sewer lair, Raph is fuming in rage about what he heard from that call, he gets April to come over to help with Donnie's computer, and together, they track down Donnies gear and find out that Draxum's lair was rebuilt, but it couldn't have been Draxum the one who did it, they've been keeping a close eye watch on him ever since he arrived and he didn't contact anyone so far, so someone else is behind this and whoever it is, it wants them to go after Donnie, this is most obviously a trap, but who's setting it up? Maybe someone from the Foot clan survived and is searching for revenge? Probably the Lieutenant? Whoever it is, they won't go easy on them if they dared to lay a single finger on their brother.
April and Raph gather Leo, Splinter and Draxum, that is not fully healed, his mystic powers are still very weak but his physical condition is already as perfect as it can get, so he can go along too, it's his Lair afterall, he should be able to help out wth a little hand.