A car accident at the Chicago Marathon turns what was supposed to be a fun day into a chaotic one, and forces the Chicago Med team to spring into action on Thursday's episode.

An exclusive sneak peek shows April (Yaya DaCosta), Noah (Roland Buck III), Nina (Patti Murin) and Dr. Halstead (Nick Gehlfuss) responding to a patient. Even though he's in over his head as a medical resident, Noah decides to act quickly in an attempt to save the person's life. But according to Dr. Halstead, he may have made the wrong call.

In a rare moment of self-doubt from Halstead, he's the one who hesitates to pull the trigger on taking extreme measures to try and save the man's life, while the rest of his colleagues are ready to jump in. Will the delay cost the man his life?

Check out the clip to get a first look at the crisis.

Chicago Med airs Thursdays at 9/8c on NBC.