Prologue
Mokuba Kaiba had always seen his older brother as being invincible. He never thought anything truly bad could happen to him. Seto had practically raised him, it seemed like. Their mother had died shortly after giving birth to Mokuba, and their father had died of cancer when they were both young. Seto had always stood up for him, always protected him, and was always there to rescue him.
This view changed when he was twelve and Seto was eighteen. The elder Kaiba was complaining of severe headaches, but said they were probably stress induced. He finally agreed to go to the doctor after weeks of feeling extremely fatigued. The doctor ran a few tests, and said that he would call within a few hours with the results.
With a heavy heart, the doctor informed Seto that he had leukemia. The good news was that they had caught it early. They did a bone marrow transplant and chemotherapy, and by the time he was nineteen, he'd gone into remission.
The chemo treatments were brutal on Kaiba. He would be in the hospital for weeks at a time. Mokuba never left his side for a minute. Occasionally Yugi, Joey, Tristan, and Tea would visit, but they came more for Mokuba's sake than Kaiba's. They would sit and make idle conversation and ask if either needed anything. That was how it went for a year.
Kaiba went to have a physical every six months after going into remission mainly to make sure he was still in remission. For awhile, everything came back negative. He was perfectly fine, which is why he thought nothing of it when the familiar fatigue set back in.
When he was 21, he went to the doctor for his biannual physical. They took a blood count. The results were not as expected. He had an abnormally high white blood cell count, and an abnormally low red blood cell and platelet count. He was told that they would run further tests to rule out the possibility of the cancer returning.
Eventually, the phone call came. Kaiba was in his office when he got it. "Mr. Kaiba," the doctor said over the phone. "I'm sorry to say that the cancer has returned."