On the season 4 premiere, we're joined by the Laser Time Network's own Diana Goodman!

This week, the staff must navigate being constantly filmed by a documentary crew, Mark is unfortunately still an absolute jerk, Dr. Elizabeth Corday makes her debut, a good Samaritan suffers a critical injury after saving a man's life, a brawl breaks out in the middle of the ER, Morgenstern suffers a heart attack, and oh by the way, this entire episode aired live on NBC. Twice.