|Portrayed by||Walter Wong|
|First appearance||Building 26|
|Date of death||2007|
|Occupation||Building 26 Analyst|
|Significant other||Unnamed wife|
|Child||Two unnamed children|
At Building 26, Nathan and Abby Collins hear shouting and an alarm rings. They walk into the corridor and see Tracy holding Mark hostage, holding him by the neck with her chains. Nathan distracts Tracy and Mark manages to get free. As he moves to subdue her, Tracy grabs his arm and freezes him. She pushes him into a wall and he shatters.
- According to the casting call, this analyst is 30 years old, and is somewhere between 5'9" and 5'10".
- For other uses of Mark, see Mark (disambig).