- "Sir, I'm afraid of death".
Proud One is the first and last diagnostic level of Patient Zero. Although it's the last diagnostic level, Dr. Cunningham still appears in the other episodes like in "Friends" and after "Twisted Rosalia".
At first, the patient is going to say that "they haven't got orders yet". To start diagnosis, you have to start with visual examination until you have seen all the obvious symptoms until RONI says the Army sent orders.
After RONI tells you that you can start the diagnosis, when you ask Samuel questions he'll say he has "chest pains", "bloody sputum", "numb left arm", and "swollen fingertips". He doesn't report this symptom, but in the physical examination his left eye is hanging unnaturally, which means that he has "blepharoptosis".
After all of the symptoms are recorded, Gabriel will request an MRI and an X-ray. In the MRI there are no abnormalities in the scan, but in the X-ray it'll show some tumors in the top left part of the lung (a "Pancoast Tumor"). The last symptom will be found in the sputum cytology; it will have positive malignant tumor cells. After that he'll be diagnosed with the Pancoast Tumors.
- "Patient diagnosed with Pancoast tumor. Continuing diagnosis to monitor status and investigate unknown lung shadow."
When you diagnose Samuel with "Pancoast Tumors" Phase 2 will begin. Phase 2 occurs because Cunningham worries about Samuel; the patient diagnosed with "Kaposi's Sarcoma" went into drastic conditions, so he thinks Samuel will go to dangerous conditions like she did. For this reason, he continues with the diagnosis.
The patient will report a new symptom like a "Stomachache", but more symptoms will appear in physical and diagnostic results like: "Jaundice", "High Total Bilirubin", "High AST Level", High ALT Level", "High y-GTP Level", "High LAP Level", "High PIVKA-ll", and "High AFP Level". After you have matched all these symptoms Gabriel will request a CT exam, and a scintography will show Samuel's swollen liver and odd shaped tumors.
Cunningham will be surprised after seeing the odd tumors, then diagnose Samuel with a "Malignant Liver Tumor". Then Phase 3, the last part of this diagnosis, will begin.
- "Continuing diagnosis to investigate the abnormal shadowing discovered in liver, along with shadowing in the lungs."
After the patient is diagnosed with "Malignant Liver Tumor", RONI reports that he collapsed and Phase 3 begins.
When you start diagnosis the patient "can't cooperate with Gabriel", due to orders from the higher-ups. RONI comes up with a good idea to continue "talking like best buds" and put it like a "memo" or a "friendly fact". The symptoms that the patient describes are "Muscle Pains", "Headaches", "Anemia", "Fever", "Pigment Spots on Skin" (which are the bruises that the "Rosalia Virus" creates), "Bloodshot Eyes", "Hematemesis", "Skin Hemmorraging", "Low Blood Pressure", "Low White Blood Cell Count", "Low Fibrinogen Level", "High APTT Level", "Low Platelet Count", and lastly "Positive Antibody Reaction".
Then, the patient is diagnosed with Viral Hemorrhagic Fever. A scene will then begin where Gabriel gets mad at Jacob Tillman and cannot escape USAMRIID. Tillman secretly makes a plan for Gabriel to escape. After he escapes, Tillman gets arrested by soldiers and the mission ends.
- The bones that USAMRIID discovered were the bones of Albert Sartre, who died of the Rosalia Virus, or viral hemorrhagic fever. This means that the patient contracted the Rosalia Virus from Albert's remains.
- It's never shown whether the patient dies of his infection or that he survives, but it's unlikely. Gabriel said that "it kills within days," and Naomi Kimishima remarks in the episode Demons and Death that "[Albert Sartre] died like the man Gabe diagnosed... Hemorrhagic fever."
- The tumors that were found in Samuel's lungs and liver are shaped oddly. These may be the "Virus Colonies" that the Rosalia Virus creates, like in the endoscopic level with Tomoe in Patient Zero.