An Insidious Trap is an Exhibit Encounter card. It first appeared in The Curse of the Dark Pharaoh (Revised Edition) expansion.
A plain, unmarked crate sits on the sidewalk. If you choose to open it, gain 2 Exhibit Items, and a gate and a monster appear. If you choose not to open it, nothing happens.
Move the Ancient Whispers marker to the Miskatonic University Street Location.