By the third film, Amanda is depicted as ignoring John's modus operandi by creating inescapable traps that kill the subject regardless of whether or not they successfully complete their test. She also displays tendencies of cutting herself under stress. The dying John decides to put Amanda through a test to see if she is still stable enough to carry on his work by having her work with Dr. Lynn Denlon to keep him alive while she oversees the tests of Jeff Denlon. Amanda acts abusively toward Lynn, jealous of the attention John is giving her, even having a fight with her at one point. At one point, she goes into another room to find an envelope that John told her about before his surgery; she finds a letter inside it which causes her even more distress, and, upon reading its contents, she breaks down and cries. While John is being operated on, he becomes delirious and professes his love for his ex-wife, but which Amanda mistakes as an undeserved professed love for Lynn. Amanda becomes angry and refuses to remove the shotgun collar from Lynn, which will kill her if John flatlines. A heated argument about John's ethics and whether or not Lynn learned anything ensues, revealing that Amanda made her traps inescapable because she felt that the victims wouldn't have learned anything from the test they were put through, and ending with Amanda shooting Lynn in the abdomen just as Jeff walks in. Jeff witnesses this and shoots Amanda in the neck. As she dies, a saddened John explains the nature of her test - Lynn and Jeff are in fact husband and wife – and expresses disappointment at her effectively defeating the point of his actions by giving her victims no chance to learn from their tests.