New Script Idea

I have a new idea for a script.
There's a little boy and girl, brother/sisters, who, when they were young, were taken away from their teen parents. They were put into their grandparent's care, but after six months were put back with their parents.
About twelve years pass, and they have no memory of this.
On a visit to their grandparent's house, their grandparents feel that it is time to tell them the truth. They show the kids videos of themselves from twelve years ago, and they get angry at their grandparents, blaming them for leaving them in such a horrible household.
After listening patiently to their grandkids yell, the grandparents finally tell them that it's not the way it happened... and tell the kids the real truth.
Right then, in that moment of silence, the parents call and tell them that they won't be coming to pick up the kids.

I don't really know how the end will work out... I don't really know how any of this story is going to work out. It'll just be a dramatic one-act play. I think great ideas will come to me...