You have created the time machine in the year 2112. As anyone would do, you traveled to the future.
However, the future was bleak. Not only were there rampant pollution, there was widespread destruction. This was caused by the past people (2017) who cleared land, destroyed habitats, and poorly disposed of their trash. Due to a mix of nuclear radiation (from the nuclear waste), and the rise of a evil in this future, the trash has risen up, and aims to turn the world into a trash heap.
You, of course, wish to return to the past and warn the people of the danger...
But your time machine was one-use only. Tsk, tsk. Hence, you had made your final stand in the city of Singadon. Will you triumph?