Algernon is a drug created by Kinga and Max that artificially increases the user's intelligence. It was taken by Synthia, which brought her above usual clone intelligence. Once she reached this level, she recognized the danger of taking Algernon and ceased its use.
Behind the scenes
Algernon is named after a laboratory mouse who has undergone surgery to increase his intelligence by artificial means in the short story (later expanded to novel length) "Flowers for Algernon" by Daniel Keyes.