Flowers for Hobbes - S1.E17

Hobbes and Darien are on the trail of a sperm thief. A college professor is using the sperm to isolate intelligence-causing genes, and put them into a retrovirus. Hobbes is accidentally infected and soon begins to become more and more intelligent. But the partners discover that the gene therapy is lethal. Bobby becomes smart enough to create a cure...but refuses to do so, preferring to die smart then live dumb. Darien infects himself, leaving Hobbes no choice but to come up with a cure to save his friend.