Luke, Mark and Max moved their shared legs and walked downstairs to Luke's living room. On the couch was Zack, Mark and Max's younger brother. But, Zack looked different, because he had what looked like a second head! And it was a head. Zack was now sharing a wider body with a new twin brother, and neither seemed to be aware that the new brother had only existed for less than ten minutes!
By quickly searching some new memories, Mark and Max learned that their new brother was named Jack, and that his head was on the body's right-hand side--Zack-Jack's right. They were watching a TV show, but not one that Luke or the twins could recognize at the moment.
Then Zack noticed his [now three] brothers coming down the stairs. He and Jack got off their shared butt and began to walk around the couch.
"Hey, bros," Zack said.
"How's it going?" Jack asked.
"Great, Jack," Mark answered.
"Ready for dinner?" Luke asked.
"You know it!" Jack replied.
Zack and Jack walked out of the living room and into the kitchen. The trio waited for a moment to decide what to do next.