Agent Walker was a special agent working for the Federal Bereau of Investigation. She was assigned to help the Mogadorians hunt the Garde, having been tricked into thinking the Mogadorians simply want to trade weapons for their help. She has distinctive red hair.
She is known to work alongside Agents Purdy and Noto.
Biography
Paradise
At some point after being recruited for the Mogadorians, Walker goes to Paradise, Ohio to investigate the destruction of the Paradise High School. She follows Sarah Hart and tries to gain information, about Number Four and Sam Goode, from her and Mark James.
Sarah is later detained and interrogated by Walker, Purdy and Noto following Four's return to Paradise. When Sarah is taken to Dulce by the Mogadorians, Walker and Noto arrive at Mark's house and ask him if he knows what Sarah was doing the night she disappeared and break the news. Walker looks sad for Mark but it is unlikely that she does not know exactly where Sarah is. (Return to Paradise)
Capturing Four and Nine
Walker and Purdy are able to track Four and Nine, presumably trough their chests. They ambushe them in an abondoned house in West Virginia and Four and Nine are locked in glass cages in the back of a van. They manage to escape and the van is involved in a crash in which it is flipped several times, throwing the agents around like rag dolls, severely injuring them. Four tries to get information about Sam and Sarah from Walker but she is slipping away, he goes outside to help Nine and when he returns Walker has disappeared.
Dulce
Walker is later seen, bandaged and slinged up at the Dulce base in New Mexico. She meets Six in her cell which she shared with Sarah and reveals her motives for assembling with the Mogs, that she's only interested in invincibility by using the alien weapons and iridium to be 'light years ahead of any other army on earth', she then takes Six from her cell and leads her away to battle with Setrakus Ra.
When she is spotted by Four, Eight and Nine, they restrain her and in fear, she reveals she knows where the Garde's ship is located (although it's unknown whether she's telling the truth or just bluffing to keep the Garde from finding Six), Nine hangs her on the light fitting and Sarah is assiged to make sure she does not escape. (The Rise of Nine)
It is unknown what happened to Walker following the Battle of Dulce and the subsequent destruction of the base caused by Adamus.