drop in (at, on) (uninvited)

(амер.) нагрянути в гості; вдертися; забігти (до когось); зазирнути (до кого-небудь); зайти на вогник (Eversmann’s Chalk Four was part of a force of U.S. Army Rangers and Delta Force operators who were about to drop in uninvited on a gathering of Habr Gidr clan leaders in the heart of Mogadishu, Somalia. - Bowden, Mark. `Black Hawk Down` - p. 3)