Where on another world are my friends?!

- Alex and his friends decided to spend the last week of summer vacation in a summer outing in an underground river park in Palawan, Philippines. They went into a tour but were separated from the main group. While finding their way out, they discovered the ruins of an ancient civilization. When they tried exploring this they were shrouded in bright light and were transported in another world. Their names, races and probably genders were changed but memory of the past was still intact. What will they do in this new unknown world and how will they meet each other again.