Colonel Graff is a marine official, stationed on Marine HQ of the Mars Outpost.

Once Lt. David Whitlark promised that he'd give some reports by Tuesday and Graff complained by e-mail. Whitlark apologised, mentioning his addiction to an old video game, and promised he'd deliver them on that day.

He had some debt to Kronos; when the latter decided that Dr. Bradley Jensen was becoming troublesome, he ordered Graff to fire him. Graff complied, asking their debts to be even.

After Whitlark went to look for the yellow keycard and failed to report back, he sent an e-mail to all personnel about his disappearance.

Dr. Guerard and Mr. Nadira asked Graff for assistance to move their equipment from the research laboratory to the Reactor room. In reality, it was Kronos who e-mailed to Graff to order him. Graff questioned it, stating that the energy demands were met, but Kronos replied that he wanted more energy for his next plans.