Sir Keren's Gem is a blue gem that was owned by Sir Keren, who often used it to hypnotize people to either extract information or bend them to his will. However, Malcolm has said that it is possible to resist by focusing on a positive, happy thought, and pushing the stone out of their mind, and using another stone or other focus point also helps. This is shown when Alyss does this, thinking about Will and using a stone that Malcolm gave her to counter being hypnotized.