I focus my other eye past the side of the weapon and see a man in a khaki trench coat. He pulls back his gas mask to reveal a ring of white hair and a fat, crooked nose that looks like it’s been broken more than once. I find myself looking forward to breaking it again.

–Number Four, The Rise of Nine

Agent David Purdy is one of the special agents of the Federal Bereau of Investigation who is assigned to help the Mogadorians hunt the Garde, having been tricked into thinking the Mogadorians simply want to trade weapons for their help. Purdy is described as being old with a ring of white hair and a fat crooked nose that looks like it has been broken more than once.

Purdy is one of the Humans that took Augmentation injections and believes they would make him invincible.



Having been assigned to aid the Mogadorians, Purdy travels to Paradise with Agent Walker and Agent Noto and occupies Sheriff James' office at the Police Station. Mark James comes across his name in a conversation with Guard on the Aliens Anonymous site and then again later when he discovers that Purdy has taken his father's office. Guard rings the number given to Mark by Walker and speaks to Purdy and discovers that the FBI know about the Mogadorians.

Purdy later attends the interrogation of Sarah Hart following Number Four's brief return to Paradise.

Mark's online contact, a blogger known as Guard, is able to hack information on Purdy including bank account details and passwords. Mark decides to break into the station for a second time and see's Purdy in a confrontation with a Mogadorian who is angry that Four had managed to escape again. When they leave, Mark breaks into Purdy's office and accesses his laptop, discovering that Sarah had been moved to the Dulce Base. When Purdy returns, Mark steals the laptop and escaped through the window (Return to Paradise).

Capturing Four and NineEdit

Purdy and Walker track Four and Nine and burst into the abandoned house carrying Mogadorian Cannons. They lock them in glass prisons in the back of a van. However, the van crashes and Purdy and Walker are badly injured. Four tries to get information from them and in the short time he leaves the remains of the vehicle and returns, he finds that Purdy and Walker have both disappeared.


Purdy survives the crash with an arm injury, bruises, and a limp, and later picks up Six from the abandoned town in the desert when she is teleported to New Mexico. He drugs her and tries to get information from her, getting annoyed when she pretends she knows nothing. He reveals that the US Government are working with the Mogadorians and that they have their Ship (The Rise of Nine).

Heart Attack and MogProEdit

Agent Walker reveals that Purdy died from a heart attack at Dulce when she approaches the Garde at Ashwood Estates. She discovered that he had been taking MogPro injections when the augmented parts of his body disintegrate. Because of this, Walker and many other FBI Agents ally themselves with the Garde in hopes to stop the Mogadorians (The Revenge of Seven).