Tom and Clare say goodbye as Clare leaves to the movies for 4 hours
After he closed the door it created a cross breeze with the opened window and caused the yellow paper to go flying out the window
Tom then watched that yellow paper glide to the far edge of the building and decides he's going to try and get it
As he's right on the edge, he becomes paralyzed with fear.
He uses a match and paper to try and get the attention of a man in the building across
He barely made it back to his window but tripped and the window closed. So he knelt on the ledge and tried a number of things to get the window open and/or get another person's attention for the building across from him
Once he finally got back in the apartment by breaking the window. He was going to find Clare, but opening the door caused another draft with the open window and he laughed as he watched the yellow paper glide out the window once again