When the case against a popular sports star falls through, Benson digs into the suspect's past to uncover additional victims; Velasco is disappointed when he meets one of his heroes.
An Indonesian man who doesn't speak English arrives at the hospital with a mysterious illness; Dr Halstead attends Maggie's family reunion; Dr Rhodes accepts a complicated heart surgery without consulting Dr Latham.
Dr Charles is forced to make a serious decision about Caroline and his relationship; Maggie meets her sister's new boyfriend; Dr Rhodes suffers a loss; Dr Choi and April face an unexpected challenge.
A patient's reticence to tell the doctors that she is transgender leads them to misunderstand her medical issues.
Mac and Riley head overseas together to prevent a governmental collapse and inadvertently inhale new deadly microscopic technology.