In 2351, Dekon and his assistant, Surmak Ren, developed the aphasia virus as a booby trap intended to be deployed aboard Terok Nor against its Cardassian crew. The virus did not deploy until nearly twenty years later, after both Dekon's death and the abandonment of the station by the Cardassians. At that time Surmak, after some coercion by Kira Nerys, helped devise an antidote for the virus which had infected the new Bajoran owners of the station.
Dekon Elig died on stardate 39355.5 at 0300 hours of neural trauma from phaser fire in the Velos VII internment camp on Velos VII, while attempting to escape the camp. A certificate was on file in the Bajoran Archival Records to document his death.
Dr. Julian Bashir, while working to counter the effects of the virus, remarked that he would have liked to meet Dekon, calling his virus a "work of genius." Surmak, examining Bashir's notes on the virus, echoed this sentiment, saying there was no doubt Dekon was a "brilliant" man.(DS9: "Babel")