They are Drew and Doyle's parents, therefore they are Zak's grandparents. They went camping in the Himalayas with their children. During the night, the camp was destroyed, presumably by a snow storm. In And Your Enemies Closer it turns out that V.V. Argost/The Yeti actually killed them, much to Drew and Doyle's dismay.
- It is unknown why V.V. Argost attacked the camp possibly the blackwells were cryptozooligists too or he just wanted to keep them from finding out the yeti exists. However, it was revealed that he just killed and stole for pleasure.