'Chicago Med' season 2 episode 9 spoilers: Dr. Charles makes a difficult decision; Dr. Choi learns a valuable lesson

April (Yaya DaCosta) encounters a setback, while Dr. Choi (Brian Tee) deals with a case involving two fighters that will teach him an important life lesson along the way in episode 9 of NBC's hit medical drama "Chicago Med" season 2.

Titled "Uncharted Territory," the show's next episode explores a different side of most of the characters. According to the official synopsis, Goodwin (S. Epatha Merkerson) enlists Dr. Charles (Oliver Platt) to evaluate a patient who wants to become a heart recipient. Dr. Choi deals with two MMA fighters who are brought into the hospital in bad shape, while Jeff (guest star Jeff Hephner) makes an unexpected confession to Dr. Manning (Torrey DeVitto).

Elsewhere, April finds out that her TB medication may lead to more complications in her health. After completing his sabbatical leave, Dr. Stohl (guest star Eddie Jemison) returns to the hospital. During his first day back in Chicago Med, he immediately offers up a different medical opinion about the treatment of a patient under Dr. Halstead's (Nick Gehlfuss) care.

NBC recently released a new promo clip for the program's midseason premiere, and it features a case that puts Dr. Charles in a difficult spot. "Courage. Hope. What Chicago Med embodies is the spirit of the city," the background voice says.The clip shows Goodwin approaching Dr. Charles and tells him that he needs to "evaluate a potential organ recipient."

As the video hints, Dr. Charles will be forced to choose between life and death. The next scene cuts to Dr. Reese (Rachel DiPillo) talking to her colleague about his decision on the patient's transplant. At the end of the teaser, Dr. Charles and Dr. Rhodes (Colin Donnell) are having a heated discussion because it seems that they have opposing views on the matter. "Someone's gotta make the tough decisions here," Dr. Charles tells Dr. Rhodes just before the clip ends.

The second season of "Chicago Med" returns on Thursday, Jan. 5, at 9 p.m. ET on NBC.