Answer:
hope it helps
They dont tell accurate age but it is said he is 16 or 17.
Their is no particular date that when he was born nor discussed in the whole movie.
In his blood contains the cure of the disease and Thomas doesnt know it yet.
Thomas and Teresa both work together for WICKED. they both help WICKED built the maze but their memories are wiped out when they were sent in the maze.
wanna know more about Thomas or the other Gladers, then comment.
