Matthew Kane

Corporal Matthew Kane is the main protagonist of Quake IV.

Biography
Nothing is known about Matthew Kane's early life before the events of Quake 4, but it seems likely that he received a typical Lunar upbringing in the years before the Strogg invaded. At some point around or following the outbreak of war, Kane enlisted in the forces of the Global Defense Force, subsequently transferring into the Terran Coalition of Man's Space Marine Corps around the time of its formation, wherein he would attain the rank of Corporal.

Above all else, Cpl. Matthew Kane is a survivor. He was aboard Space Station Armstrong when the Strogg launched an overwhelming attack on it, and he was the only person to emerge from it alive. He is the only one who knows exactly what took place there, and he is under the strictest orders to remain silent on the matter.

After several months of recuperation, Kane was assigned to the world-renowned Rhino Squad. This was thanks to Lieutenant Voss, who saw Kane's potential to be a truly valuable asset to the team. However, the squad only knows a sparse handful rumors about how he survived the attack on Space Station Armstrong. They've never worked with him, don't trust him, and question if he might be a loose cannon who will put them all in excess danger. Still, with their fates now so intertwined, it's time to adapt or die once again. Given their upcoming mission on Stroggos as part of the huge second invasion force, they will quickly find out just what Matthew Kane is capable of.

Stroggos
Kane never speaks during the game, but he most likely narrated the Quake 4 trailer with these words about the Strogg:

It is revealed during the game that Kane is the only known survivor of the attack on Space Station Armstrong, which may have taken place at the start of the Strogg invasion of Earth. He is reassigned to Rhino Squad, where he serves in the second retaliatory attack on Stroggos. His left eye was a cybernetic implant, as the original was lost in the events on Space Station Armstrong, after which he looked like he had been "mauled by a dozen pitbulls".

Stroggification
While attempting to destroy a Strogg facility, Kane is defeated and captured by the Makron. Deemed suitable for immediate cybernetic augmentation, Kane is taken to a Strogg Medical Facility and shackled to a metal slab mounted on an assembly line. In line for stroggification behind another captured marine, Kane witnesses the gruesome process used by the Strogg to create their soldiers right before he himself is subjected to it.

A laser scanner checks Kane for unknown parameters before he is carted off to the next station, where a large hypodermic needle pumps enormous amounts of adrenaline into his chest. He is then checked by one of the facility's Strogg scientists, who appears to inspect the wound, gives him another injection, and partially lacerates his face.

The next station is particularly gruesome. A circular saw, mounted on a mechanical arm, proceeds to messily amputate Kane's lower legs above the knee and burn his stubs to ensure Kane does not bleed to death; Kane blacks out.

After regaining consciousness, he is transported to the next station. Mechanical legs are grafted onto the remainders of his thighs, and a system of armor plating is riveted to his torso and extremities.

The fourth station installs a control chip — the neurocyte — in Kane's brain using a large hypodermic needle. He instantly gains the ability to read and understand the Strogg language (however, all "E" letters are mirrored to "3" on the HUD).

After this, Kane receives armor plating on his backsides (this is not shown in the game, but this plating can be seen in several cutscenes). Finally, Kane is put into a tank and transported to the neurocyte activation site, A device is placed in his breast.

The final stage of the process involves the activation of the neurocyte, allowing the subject to be remotely controlled. Before this can take place, however, Kane is rescued by his squadmates.

Continued Campaign on Stroggos
As a result of the operation, Kane is faster, stronger, and has superhuman stamina. He also gains the ability to use certain Strogg technologies, such as teleporters and health stations. Of particular note is his immunity to Strogg laser defense grids, which are instantly lethal to unmodified humans on contact.

Following a medical examination back aboard the USS Hannibal, Kane is greeted by squadmate Lance Corporal Nikolai "Sledge" Slidjonovitch with the words, "Welcome back Corporal Kane. May I be the first to say, you look like shit," a sentiment shared by another squadmate, Corporal William "Billy" Rhodes. The medical team that examined him state that even if they had access to an advanced medical facility, the augmentations may be too deeply connected to his central nervous system to be removed safely.

Kane's squadmates change their opinion when it is shown that the Strogg technology embedded within Kane's body can potentially help the humans destroy the Strogg Nexus. When Kane does indeed defeat the Nexus, he only receives a brief three minutes of congratulations from Rhino Squad before he finds that he will be receiving new orders, and shall once again have to plunge into the heart of battle.

Trivia

 * Matthew Kane bears some resemblance to the character RoboCop from the "RoboCop" movie trilogy in general body and head shape.
 * Kane is the only character in Quake 4 that can use all weapons except the Gauntlet.
 * It's unknown what happened to Kane after the events of Quake 4, though it is presumed his Strogg parts are still kept.
 * His Strogg designation is 8462-9B.
 * He shares his family name with John Kane, the protagonist of the Doom 3 novel trilogy and its expansion Doom 3: Resurrection of Evil.