Disclaimer: Don't own them.
Leo and Donnie didn't mean for it to happen, they didn't think that anything serious would happen, and they only did it to get Raph free so they could go back to Earth. They didn't know the stuff they made Mikey eat would make him sick. I mean really sick.
Raph was woken up in the middle of the night to a sound that made him nervous. He got out of bed running to the bathroom it sounded like someone was sick."Mikey, what's wrong bro?"All he got was a frightened whimper to be followed by more vomiting. He got down on his knees and was rubbing circles gently on Mikey's shell. "Gonna get Donnie k."Mikey just nods his head ok and then continues to puke. Raph runs to Donnie's lab, shakes him awake, and says, "Wake up Mikey needs ya come on." Don jumps and follows Raph to where Mikey is. By the time the get there Leo is in the bathroom with Mike. He's holding their lil' bro against his plastron, using a cold cloth wiping it against his face and head. "He passed out as soon as I got in here and he's burning up."
"Let's get him to the lab so I can figure out what is going on."
Leo carried Mikey to the lab and laid him down on the bed. Donnie quickly started taking vitals, drew blood, and covered him up. He soon noticed something strange even though Mike was burning up his temp was low, which he told the others didn't make sense. He took some of the blood to put on a slide for the microscope and put the rest through his machines. Upon examining the blood he noticed a grayish substance attacking Mikey's cells. Just then on of his machines went off signaling it found something. Don rolled his chair over to exam the results and gulped, "Leo this is kind of our fault."
"Wha' do ya mean brainiac?" Raph asked.
"Well when we escaped the Triceratons, to rescue you we had Mikey eat that one stuff, and it's attacking his system. I swear if I had know I would have thought of something else Raph."
"So l't m' g't this straight ya and fearless poisoned our baby bro just to free me, are ya two stupid, I would rather be stuck instead of this, and ya betta fix it understand." With that Raph stormed off to the dojo. Leo walked over to Mikey running his hand across Mike's forehead, "I'm so sorry Mikey."