A hacker demanding a ransom payment shuts down the hospital computer system, forcing the doctors to diagnose patients without the aid of technology. A stressed Goodwin struggles to keep the hospital afloat when an unexpected visit from her ex-husband Bert and his new girlfriend make matters worse. Making use of his former navy experience, Dr. Choi and Noah have to locate a bullet inside a patient with a gunshot wound. Meanwhile, Sarah feels Dr. Charles may be trying to push her out and Robin's unusual behavior worries Dr. Rhodes.