Rapid skin growth toxin Appearances Mentioned Effects Victims Perpetrator Solved A rapid skin growth toxin was featured prominently in the episode "Ability". First diagnosed when Patient Holly Musto came into Walter's office with an extra nose growing. She also had a funny smell coming from the growth. The toxin causes scar tissue to grow at a rapid rate. It seals all orifices, killing the victim. At one point, Olivia tried to save a young FBI agent who had come into contact with the toxin, but the growth was too fast.