NBC’s “Chicago Med” is serving up another intense case that is sure to test the doctors at the hospital next week. This week, fans saw Dr. Will Halstead discover that Maggie’s sister Denise has cancer while Dr. Connor Rhodes performed an impossible surgery on an important and wealthy patient.

In the end, Rhodes’ (Colin Donnell) new mentor, Dr. Latham (Ato Essandoh), had to break his Shabbat and save the patient from certain death since he could not pull off the time-sensitive operation. So, what will happen next Thursday?

The official synopsis of “Brother’s Keeper” on NBC states that a rare and unheard of infection will quickly spread throughout the hospital. The doctors will discover that several patients suffer from the same infection. This outbreak prompts Dr. Daniels Charles (Oliver Platt) to call his daughter Dr. Robyn (Mekia Cox) for help. She is an epidemiologist.

“Chicago Med” Season 2, episode 4 will see Robyn joining the team and trying to find a common link between the patients.

The promo of the upcoming episode reveals more spoilers. Dr. Natalie Manning (Torrey DeVitto) tells Halstead (Nick Gehlfuss) that the hospital might be looking at an outbreak that doesn’t have a cure. We also get the first glimpse of Robyn as she tells the doctors that every patient in Chicago Med is at risk.

Later, Manning puts the blame of the outbreak on herself since she missed the diagnosis of the first patient’s disease.

As episode 4 progresses, things get worse inside the hospital. The infection spreads quickly.

Meanwhile, Dr. Choi (Brian Tee) and Rhodes work on a very ill elderly man. But a conflict arises between the man’s son and his girlfriend on how best to treat him.

Elsewhere, Dr. Sarah Reese (Rachel DiPillo) will help a young drug addict.

Catch “Chicago Med” Season 2, episode 4 on Thursday, Oct. 13 at 9 p.m. EDT on NBC.