Egon: Don't cross the streams.
Egon: It would be bad.
Peter: I'm fuzzy on the whole good/bad thing. What do you mean, 'bad?'
Egon: Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light.
Ray: Total protonic reversal.
Peter: Right. That's bad. Okay. All right. Important safety tip. Thanks, Egon.