Marc Kubacki appears on The Baby SItters Club Super Special #1. Marc is a seven-year-old boy, who has a heart condition, and uses a wheel chair. He meets Stacey McGill, who is a member of the BSC (Baby-Sitters Club).
Marc meets Stacey on the Cruise Ship that they are taking around the Bahamas, Which leads them ending off with three days of fun in Disney World.
Stacey and Marc are related, such as they both have a sickness that holds them back from things: Stacey is hold back from sugary foods, and Marc is held back from anything wild: Roller Coasters, Merry-Go-Rounds, and lots of other things.
Later in the story, Stacey introduces Marc to Claire, a five-year-old Pike, and Margo, A seven-year-old Pike. They become friends, But Claire and Margo want to know things immediately: Can he walk? How does he go places? Does he sleep in his wheelchair? There is only one way to find out: Being Friends!
In the end of the Super Special, Marc has surgery, to make him able to walk and do things that he wasn't able or allowed to do before.
Marc and Stacey became Great Friends. Stacey even insisted that the trip wasn't over until the Baby-Sitters had found out how Marc's Surgery went.
It went just fine, although Marc suffered many infections when the surgery was over, but he was finally becoming to live a normal life.