Shaun and Lea's upcoming engagement party has everyone in a festive mood after their return from Guatemala. Meanwhile, a young single mother learns her son may have contracted his cancer from a surprising source, and Mateo finds out if his previous issues in America will be resolved.

Dr. Shaun Murphy and the team race to save a pregnant woman's baby and find her current situation as a convicted felon complicates it even more than they realize. Meanwhile, the hospital takes on some unexpected changes that the staff are not prepared for.

Shaun confronts Salen about the many changes she has implemented since coming on at St. Bonaventure. Glassman is forced to accept his new role at the hospital.

Dr. Shaun Murphy and the team treat a young girl whose father's personal research complicates their treatment plans. Meanwhile, Dr. Park, Dr. Reznick and Dr. Lim's patient refuses a life-saving lung transplant despite having a family donor

Dr. Park and Dr. Murphy treat an elderly Asian man brought to St. Bonaventure by his daughter after being the victim of a hate crime. In addition, Lea goes behind Shaun's back to help raise his negative patient satisfaction scores

Dr. Shaun Murphy and Dr. Alex Park must grapple with a life-and-passing decision and decide between saving one patient over another. Meanwhile, Dr. Morgan Reznick goes a little too far in her attempt to win Salen's favor

After visiting a possible wedding venue, Shaun and Lea happen upon a terrible car accident and discover Alma, a young pregnant mother who has been badly injured and needs immediate medical attention. Back at St. Bonaventure, Alma's condition worsens, and Shaun and Drs. Lim and Jordan are forced to deliver the baby prematurely. Meanwhile, Dr. Glassman is apprehensive when a figure from his past reaches out for help

Now that Shaun has called off the wedding, he is forced to confront Lea about their relationship and determine what he really means to her. Meanwhile, the team debate their opinions on plastic surgery and Dr. Audrey Lim hopes to expose Salen's cover-up over an infant's passing to take her down before it is too late.

In an effort to please Salen, Andrews takes on a high-profile case and assigns Shaun and Allen to help perform a risky surgery to restore the voice of a famous pop star. In addition, Reznick and Park treat a man whose 17-year-old son, Cody, is confined to a wheelchair due to complications related to Kabuki Syndrome

Salen takes extreme measures when she learns that the surgical staff have joined Lim's efforts against her. Meanwhile, the team treats a liver transplant patient whose organ donor unwittingly gave him cancer. And elsewhere, Jordan, Asher and Andrews look for a surgical solution to remove a pregnant surrogate's cancer in such a way that she won't also need a hysterectomy to survive

Dr. Shaun Murphy makes a personal connection with a precoious young patient which threatens his objectivity. Meanwhile, while volunteering at a long-term care facility, Dr. Morgan Reznick realizes she could help Dr. Aaron Glassman's clinic by offering telemedicine services for nursing homes and care facilities.

Drs. Lim, Park and Wolke treat a woman with Valley fever and discover a secret she has been hiding from her fiancé. Meanwhile, Drs. Murphy, Allen and Andrews treat a 45-year-old virgin and help her make a big decision about her life.

While Drs. Lim, Murphy and Wolke help a teenage "biohacker" whose self- experiments begin to compromise his health, Drs. Morgan, Park, Jordan and Glassman treat a young woman who wants a controversial surgery to treat her depression and chronic pain. Additionally, Dr. Reznick looks to take the next step in her relationship with Dr. Park.

When someone mistakenly brings a hallucinogen-laced dish to the hospital's company potluck, much of the hospital staff and doctors are incapacitated - leaving doctors Murphy, Glassman and Allen forced to take on all the hospital's cases, further exacerbating Dr. Murphy and Dr. Glassman's conflicting work styles.

While Doctor Andrews treats a foster kid for injuries sustained at his group home, Shaun and team look to Lea's expertise with cars and auto repair to help a patient whose iron lung has broken. Meanwhile, the patient's niece, a documentarian, takes an interest in Shaun.

As Shaun and Lea head toward their wedding day, a documentary film maker has chosen to follow their lives to showcase relationships and weddings of atypical couples.

Sophie takes Lea out for a day full of luxurious wedding planning. And after a near fatal oversight, Dr. Lim senses an underlying issue is behind nurse Villanueva's unprofessional behavior.

Shaun and Lea make a big life decision and are pleasantly surprised by the support they receive from their friends at the hospital. Meanwhile, when Dr. Wolke's parents show up with a revelation, Asher struggles to accept that he and his father may never truly understand one another.