Our mutual friend informed me of your concern for my health. With the aid of <Alias.PronounPosObj=Player>, I was able to secure an antidote for my condition, and am pleased to report that I have made a full recovery.
Although our circumstances have changed, I hope we might someday be able to collaborate on our research once again. Until then, my regards.
[Platforms needed] If you return to Virgil after you have defeated the Brotherhood of Steel, he will give you this letter to return to Dr. Li. However, the marker for Dr. Li (if you convinced her to join back the Brotherhood) will be floating over the rubble of the downed Prydwen, making it impossible to complete the quest. [verification overdue]