Peter, a well known hero known as spiderman, never knew that one day he would meet a girl from outer space, later known as his sister. What will he do when he finds out that the whole galaxy is after her?
All the Avengers except for tony didn't know their beloved Peter had a sister, So when Aunt may leaves for a work trip and leaves the kids in Tony's care, the Avengers get to meet Peters's twin sister Olivia.
(I don't, and never will own the Marvel characters)