A foreign object is as the name implies - any material that doesn't belong in the body. They are a common source of injury, and are often found lodged in the body or organ. Common foreign bodies encountered in the series include glass fragments and bullets, and this list can extend to wires, bone fragments, or even steel beams.
Foreign objects are commonly extracted with the forceps. Proper removal involves pulling the object straight out in correspondence to their shape and curvature; deviation may result in a lower score or even a miss. A scalpel cut may be necessary to widen the wound for safe extraction.