Caleb Isenberg is a NEVEC Officer in Lost Planet 3, He set his forces down on E.D.N. III after being contacted by Renard Laroche who told Isenberg that Jim Peyton was working with the Snow Pirates. Isenberg called Jim into Phil Braddock's office asking Jim if he put something else ahead of his family's safety and his job (since he knows that he is working for the snow pirates) and saying that he (Isenberg) is here for for Human race to escape extinction not only for him but for his son and everyone else and no one will get in his way. Later on during the campaign Isenberg sends Laroche to capture Jim with only to have that plan failed due to jim destroying his rig. Isenberg is later seen at the camp of the Forgotten where it is being attacked by NEVEC and he is threatening Souichi to tell him what he was hiding here. Jim manages to get there in time but little is done as Isenberg kills Souichi and before Jim can shoot him, Isenberg tells him that he will kill his wife. He shows him a video call from Jim's wife saying that the riots on earth have become too dangerous so NEVEC took them in. Jim surrendered and was captured.
Back at Coronis he is testing a machine that Dr. Kendrick Kovac created to control (and which almost destroyed Coronis earlier on) the Akrid at a specific frequency. He tests the machine to his amazement and takes it inside Nushi (a living beathing creature made up of pure Thermal Energy and which is responsible for controlling the planets climate).
Isenberg is last seen inside Nushi with his fight against Jim Peyton with a NEVEC military RIG (with weapons) where he is later killed by Jim Peyton. Due to Jim's leg and Isenberg being tied together with a rope thrown by Jim into his deployed RIG's drill, Isenberg dies but Jim however surives the ordeal but at the cost of his left leg and the death of Nushi.
Caleb Isenberg leaves behind one son, Dennis Isenberg. Caleb perhaps was one of the reasons why Dennis joined NEVEC but this is all speculation Caleb is never brought up in lost planet 1 or confirmed by capcom.
Traits and personality
Isenberg did seem to care for the Human race when he was telling asking him about his secrets and begging Jim not to destroythe machine capable of controlling the Akrid but is not hesitant to do anything to get his way and accomplish the NEVEC agenda. This fact seem true when he was using Grace Peyton as a hostage to make Jim surrender.
He did in some way respect Jim Peyton as a soldier, this can be heard through a audio log when Isenberg is talking about Jim's military life.