Doctor Stephen Strange was practicing his portal thingys and he opened one where YOU where the opposite gener of the hero/villan of your choice. unfortunatly you found the portal and seted through before he could close it. unofrtunatly since this was a new thing Strange was trying out he couldnt open it back up...so you where stuck there...eventually he restriened you it needed depending on your character and took you to the Avengers compound hoping they could help...but was hesitant because the character of yor choice was there...