contacts — the act or state of touching; a touching or meeting, as of two things or people.
knocks — to strike a sounding blow with the fist, knuckles, or anything hard, especially on a door, window, or the like, as in seeking admittance, calling attention, or giving a signal: to knock on the door before entering.
ruins — ruins, the remains of a building, city, etc., that has been destroyed or that is in disrepair or a state of decay: We visited the ruins of ancient Greece.