[Venkman is uncharacteristically quiet, so Egon decides to say something he knows Venkman won't be able to resist making a comment about. Relieve the tension.]

If it turns out he is possessed, we'll have to figure out a way to replicate the effects of the psychoreactive slime I encountered back in my dimension. That seemed to be one of the more effective ways of ejecting a possessor from its target.

[He untangles a few of the wires and reconnects a few loose ends. He then leans down to plug it into an outlet and the neural wavelength detector begins to hum quietly. Egon taps his fingers against the desk surface, clearly hesitating about something.]