Script

There will be little dialogue during the opening because 'actions speak better than words' and Hannah will be crying and drinking the potion so you don't need words to show she is reckless and emotional. Also as Kyle is more concentrated on his game than the phone call you tell that he is lazy(regular teenager).

Though at the start when Kyle is on his bed playing and the phone is ringing and Hannah is in the lab, they say:

Kyle: Eh, I'm playing
Hannah: Kyle, pick up!
-                                                                     puts down phone
Hannah: This is your fault (look at phone)

Then when Kyle rings back he says:
Kyle: Don't do anything stupid, you know your not supposed to be in your parents lab!

And finally when Kyle is getting chased:
Kyle: This was all my fault, all of mankind could be lost because of me. I must resolve this mess and find the cure.

This short bits of dialogue help the audience realise that there's been a mutant virus epidemic and that Kyles girlfriend started it all. Also it gives a bit of Kyles character away, like him being lazy but caring deep down.