"'Will you walk into my parlor?' said the Spider to the Fly." - from the poem "The Spider and the Fly" by Mary Howitt.
The crucial moment in George Sluizer's chilling psychological thriller "The Vanishing"(1988) can be summarized with that quote. The Fly cannot resist the offer, simply because of his intense desire to know. The Spider cannot resist making an offer, only because of his cold curiosity about the result. He has a solid prediction based on his careful calculation, but he wants to know the result in his cruel experiment, like he previously tested himself before.