Prepared for multiple casualties, the medics attend a crash involving several vehicles. One driver is suspiciously unconscious, although his body shows no signs of trauma. Elsewhere, a pedestrian is struck by a car and the trauma team perform a series of tests to establish the cause of his amnesia. Response time is always critical for the trauma staff – never more so than when paramedics rush to a reported shooting incident. This time, however, it turns out to be a hoax. Also this week, a hospital transport worker eventually regains consciousness, but the cause of his symptoms remains a mystery. Finally, when a man collapses in the street, the staff of the Physician Response Unit look for any clues to his condition. It could be anything from a pulled muscle to a full-blown heart attack, and prompt diagnosis will be crucial.