Dr. Hugo Razo treats injuries a young couple sustained during a violent home invasion. Transplant surgeon Jonathan Chen is stunned by the grotesquely enlarged heart of a young Marine. If he can't find a solution to bring Chris Molnar back to health, this gung-ho youngster will lose more than his dream of serving in the armed forces--he'll probably lose his life. ER doctor Debbie Yi recounts the family trauma that drove her into medicine and proves that there are silver linings to every decision. Strong-willed ER nurse Marina Dedivanovic is back in the ER confronting everything from tough men afraid of needles to feisty New Yorkers.