Of all the Fleet, the most terrifying are the Fleet Guises, who can shift and manipulate their substance to mimic images of the living and dead and hide amongst innocent people. Taking the faces of their recently slain are the best ways of sneaking up on their victims. In order to discover the Fleet Guises, one must pay careful attention to their fingers, which are weak in terms of keeping their composition. They can flicker back to the dark lavender hue of the goop, exposing their cover.