The Deleter is, according to Samus, a traitor among the Galactic Federation 07th Platoon. After the Platoon's members began dying off due to methods only conscious species would likely employ, Samus concluded that one of the six members in the 07th Platoon was killing off the others. Samus gave this member the alias "the Deleter" and referred to him as such. Throughout the events of Other M, Samus is suspicious of part of the crew at some point, even suspecting Anthony Higgs and Adam Malkovich. Though the Deleter's true identity is never revealed, it is implied that James Pierce was the Deleter until, of course, he died when facing MB.
After learning that certain Galactic Federation members were behind Bioweapons Research, Samus concluded that such members had sent in a member into the Platoon, the Deleter, to silence the members after they witnessed the illegal research. The Deleter succeeded in killing Maurice Favreau and K.G. Misawa, possibly even Lyle Smithsonian, though Lyle's death may have been caused by a number of the hazardous creatures aboard the ship, such as Little Birdie.
The Deleter's Mission
Samus first encounters a person hidden in a Galactic Federation Power Suit driving the RB176 Ferrocrusher, driving the machine to kill Samus. The Deleter has already destroyed the Exam Center, and done away with Maurice. However, Samus meets MB, a witness to Maurice's death. As both of them talk, an RB176 Ferrocrusher makes the scene, piloted by the Deleter, and tries to kill both Samus and MB. Samus hurries MB away just in time, and deals with the Ferrocrusher herself. When Samus "defeats" the Ferrocrusher, it suddenly begins moving erratically, either by malfunction or Deleter's design, and creates enough havoc for the Deleter to vanish without notice. Samus, suddenly alone, moves on to other areas, while the Deleter gets to the Pyrosphere.
K.G., also in the Pyrosphere, doesn't know there's an assassin amongst them, due to the all-pervasive electronic interference. He does, however, find out about it through experience. After being flash frozen, K.G. is thrown into lava and incinerated.
Time passes, and the Deleter takes no actions against the 07th Platoon. It isn't until Samus is confronted by Ridley that the Deleter makes his next move. As Samus is panicking, Adam is yelling at her to use her Plasma Beam. Suddenly, he looks over his shoulder and a shell weapon is fired. Adam falls out of contact, and after Samus deals with Ridley, becomes worried.
Samus rushes to return to Adam, but is suddenly distracted by a masked member of the 07th Platoon (seemingly shambling along) in the Main Elevator. It becomes obvious that this is the Deleter as he tries to keep Samus from following him by retracting a bridge and destroying its console, though Samus' Space Jump makes this effort useless.
The Deleter leads Samus to the Bioweapons Research Center, but quickly hides. Samus soon enters, and by coincidence, so does MB. They have their back and forth, and Samus ultimately departs, leaving the Deleter and MB together. Alone. With confidence, although injured, confronts MB. The screen goes dark, and the Deleter manages to get one shot off.
When Samus finally returns to the Bioweapons Research Center, James' body is lying on the ground where the Deleter had confronted MB with his visor smashed in. The Deleter's identity is assumed that of James Pierce, who had died trying to silence Melissa Bergman, not knowing the woman he faced was actually the android MB.
James Pierce as the Deleter
While the Deleter's actions were sometimes indefinite, there are some other possibilities that are even scarcely hinted at.
- As the Communications Expert, James is responsible for the team's communication. He may have scrambled his own team's channels and created the electronic interference in order to keep teammates from calling for help, or revealing James' secret purpose in their last moments of life. This would also explain why only Samus' comms worked.
- The data fragmentation on the computer console in the Exam Center may not have been James' doing, and instead automated in case of security breaches. Instead, he may have been planting explosives in order to kill all of the 07th Platoon in one fell swoop. Unfortunately for him, Samus would arrive early.
- As the Communications Expert, it's unlikely James would carry enough explosives to destroy an entire building. He may have gotten the drop on Lyle and killed him for his explosives, then tossed his body aside in a place that the corpse would not be immediately noticeable. It would be by coincidence that Little Birdie finds a snack.
- One of the Desbrachian cocoons in the room James is killed disappears after he's killed. MB may have activated it to kill him, even though she's known to be perfectly capable of handling humans herself.