Operation Immortalis was a project that featured in Mutant X.
Operation Immortalis was a research initiative that began in 1943 by Colonel Henry Burns in an attempt at creating an anti-aging compound that would be known as the Sirtuan serum. This serum worked by transferring the genetic vitality of one person into another.
Burns used the Tomcat navy fighter pilots as guinea pigs in the experiment until the Dominion learnt of the gruesome deatha and show down the operation. After sixty years, Burns heart began to fail and he along with his personal physician, Dr. Francis Gallant, restart the working secretly on the last surviving Tomcats which included Jesse Kilmartins grandfather William.
The serum was temporarily effective on William and Henry until Jesse intervented after which William shot Henry in order to prevent him from continuing his research.