An embodiment may take the form of a method usable with a well including communicating an untethered object downhole in the well to land the object in a restriction to form a fluid barrier, and using an agent carried by the untethered object to seal at least one gap in the fluid barrier. Another embodiment may take the form of an apparatus usable with a well having a solid component to be deployed and be communicated downhole as an untethered object to land in a restriction in the well to form a fluid barrier and an agent attached to the solid component to seal at least one gap in the fluid barrier.