FF13 story.

Here is my take on the FF13 trailer-

The main heroine is a outlaw who gets payed to murder and steal and is well known for her brutality with her chosen weapon. In recent times a hidden civilisation has been found on the other side of a cave and the civilisation is quite basic in technology compared to the rest of the world, but it has been discovered that they hold the key to unlocking the ancient Summons of the past and upon hearing this the kingdom of Rasime sent a few soldiers into the cave and kidnaped a few of the people there to figure out the key to unlocking the secrets of the summons.(These people are the hooded figures on the train)

The Kingdom of Listium hears of this barbaric act and instead of sending soldiers in to rescue these people the King hires the famous bandit which is the main heroine, to do the job to stop any possibility of war. The heroine agrees for a price of 2000gil and sets out to the train station in the small town of Faine where the soldiers were seen heading towards with there captives, she cleverly gets there before her enemy and changes the route of the train and hides. When the Soldiers get there they ride the train thinking it will take them back to Rasime but they are wrong, the heroine suddenly jumps out and attacks defeating the soldiers and rescuing the captives which she takes back to Listium.

This is all i know so far upon rescuing the people she becomes known as a hero and with all these great victories trhoughout gets a higher social rank.

Very possible approach i can say.But i think that the guys in hoods hide a lot more than you think.Maybe you should compare them with the ones in KH II.Members of a secret organisation that have darker purposes or something like that..