Dr. Milton Isaacs (died 2016) was a scientist and physician in charge of Area 51's medical facility.
During the War of 1996, Isaacs was with Okun's side, helping to extract a capture alien from its exoskeleton armor. The alien awoke and killed or harmed everyone in the surgery room, including Isaacs. He later regained consciousness just as the alien was shot by President Whitmore's security detail, but Okun was rendered into a coma.
Since the end of the war, Isaacs spent his time researching new alien technology while also tending the comatose Okun. Twenty years later and on the upcoming anniversary of the war, Isaacs was in the middle of tending Okun when the latter suddenly woke up. Isaacs was very pleased to see Okun awake, but grew concern of his partner's strange habits, such as finding him scrawling his entire room with alien symbols.
After the return of the aliens, Isaacs brought Dr. Catherine Marceaux to examine Okun's writings and later protest his lover's obsession to breaking open the unknown cargo that was recovered by David Levinson from the Moon. When the cargo released an alien artificial intelligence which warned them of the aliens' intentions, Isaacs and Okun helped secured the A.I. in a chamber while ESD forces began their attack on the alien queen. However, alien soldiers breach into the chamber and fatally wounded Isaacs to Okun's extreme dismay.
- "Your wife is bleeding internally, Mr. President. Perhaps if we'd gotten to her earlier..."
- ―Dr. Dr. Isaacs's on the First Lady's condition.
- "I've got something I gotta tell you. This! [touches Okun's scarf] That was supposed to be a sweater."
- ―Dr. Isaacs's final words to Dr. Okun.