The only connection to the earlier movies in the I KNOW WHAT YOU DID series is a news clipping and a persistent teen legend about a boogey-man-like figure in a fisherman's rain slicker who kills young people harboring terrible secrets. A bunch of Colorado high-school seniors use the legend to play-act a public attack by the rain-slicker man in a crowded carnival on July 4. Their pointless prank leads to one of their circle getting killed, and the remaining foursome vow to keep their participation a secret. One year later, one of them, Amber (Brooke Nevin), receives the familiar anonymous note in text-message form: "I know what you did last summer." She rounds up the others to determine who could be harassing them, and soon the figure in a fisherman costume is slashing away at them again, never mind that the primary location is a closed-for-the-season ski resort, miles from the water (but still inky-black with shadows most of the time).