She Devil

Brilliant Biochemists Drs. Scott and Bach administer a serum created from a fruit fly to a sweet, dying woman named Kyra. She becomes well again but her personality changes drastically: she becomes evil, narcissistic and emotionless, committing crimes which leads to the murders of two innocent people. Kyra figures out that both Dr. Scott and Dr. Bach are on to her, but she doesn't care, basically telling them she has no intention of stopping her evil ways, threatening to kill either one of them or anyone who gets in her way. Realizing their mistake Dr Scott and Dr Bach now have to find a way to stop Kyra before she kills anyone else.