Do not engage players who seem harmless but hold surreptitious and sinister motives. Unsavory characters gain power when they are believed or not taken seriously.
Read the text from Richard Wilhelm's translation of the I Ching
The rise of the inferior element is pictured here in the image of a bold girl who lightly surrenders herself and thus seizes power. This would not be possible if the strong and light-giving element had not in turn come halfway. The inferior thing seems so harmless and inviting that a man delights in it; it looks so small and weak that he imagines he may dally with it and come to no harm.
The inferior man rises only because the superior man does not regard him as dangerous and so lends him power. If he were resisted from the first, he could never gain influence.