After all of the fusing, each of the test subjects decided that it was high time to leave the Institute for Conjoined People. The reasons that they had come here for were to keep from weirding out their friends and families, to be cared for by the conjoined staff, and by encouragement of the scientists who had made each of them what they were before they arrived. Now that they had discovered all these machines, and that they could in fact reverse transformations as well as perform them, the entire gang decided that they were likely being kept here intentionally to keep any evidence of their experiments' true nature hidden; that was about to end.
That night, after the residents were sure that the last of the staff had gone to bed, the plan was put into action. After grabbing some of the handheld machines so that any future transformation could be performed or reversed, everyone went back up to their rooms to start packing up all of the clothes, money, and other belonging that everyone owned--most of the groups that had been conjoined through the recent experiments downstairs, so they had to make sure that every room was checked and emptied of all of their belongings. After gathering together in the lobby (pun intended), they quietly snuck out the main doors and crept to their cars in the parking lot--Leo, Donnie, Raph, and Mikey went to open the main gates and make sure that the two-headed guard(s) was/were asleep. Fortunately, the guard heads were asleep, and there were no cameras to see what anyone was doing. As for the cars, most of the conjoined friends had come here with others, so--to make a long and somewhat unnecessary story short--each car was being driven back by at least one group of conjoined siblings.
Their cars started up: there was no sign of stirring from the two-headed guard, and no sign of a light or moving curtain in any of the Institute's windows. With that, the cars pulled out of their spots one by one, quietly driving down towards the open gates. The cars followed each other in a line, with Matt-Rex-Jeff-John leading the way. Soon enough, everyone had gone through the gates, and quite a few heads looked back in case they were followed or if there was any sign of danger. Fortunately, no danger was seen, and all nineteen bodies breathed a sigh of relief as the Institute disappeared behind the thick trees along the winding road. With the city only a few hours away, a good thought entered all forty-seven heads: at long-last, they were going home.