Excellent job in the set up of your story in which you give us just enough info to picque our interest which is what a good writer is supposed to do. I wonder if the mysterious men are the enemy or the protectors? Hope you continue so we can all find out:) Based on your intro about how we always thought Earth would always be here and now its gone I suggest calling your story "The Finite Earth". Just a suggestion:) Great job and welcome back to writing.