Dysek was a Dinaali doctor, the Chief of Medicine on Hospital Ship 4-2 under administrator Chellick. Dysek worked on Level Blue, which had the high priority patients.
In 2377, when Chellick acquired The Doctor's program, and assigned him to Level Blue, Dr. Dysek was one of the first to welcome him, and inform him how the medical system worked on Dinaal. A computer known as an Allocator assesses which patient has access to the best care depending on the importance of his or her profession, and skills. Later, the Doctor watched him perform a complex surgery, and complimented him on his technique.
Dysek became angry when he caught the Doctor prescribing unnecessary medication for his patients. The Doctor was trying to get medicine to level Red which was low priority patients. The Doctor warned that if they don't request more resources this month, the Allocator may refuse to increase necessary supplies next month, and their treatment rates could drop. Dr. Dysek saw the logic behind this, and hid it from Chellick, so he would receive the resources he needed in the future.
Dysek would support the Doctor in his plan to force Chellick to order adequate medical care to the low level patients in order to save their lives. After the Doctor injected Chellick with a virus that infected a low level patient named Tebbis who had died, the Allocator identified Chellick as low level and denied Chellick medication. Dysek refused to help Chellick until all Red level patients were transferred to Level Blue to receive care. Chellick finally agreed. (VOY: "Critical Care")