How characters are introduced

There are two character in our thriller which we see, there also could be another character, but this is only hinted at. We are introduced to both of our characters right at the beginning the beginning of the thriller; we see Olivia and Amelia coming down the path of the park. This is when we know that these will be our to characters. There is also a part in the thriller when there is a hint at another character; we see a point of view shot through a persons eyes; whose we do not know, and then again at the end of our thriller we see the eyes of someone we do not know.