Thomas Kelly

"Are you deaf, Marine? When I say move out, you'd better move!"

- Sergeant Kelly

Master Sergeant Thomas Kelly is one of the first characters the player meets, and the secondary antagonist of Doom 3 (after his transformation).

History
A decorated veteran of the UAC Marine Corps, Sergeant Kelly— or Sarge as he is known to his troops— is the ranking commanding officer on Mars Base. A highly motivated soldier and a demanding commander, Sarge has little patience for those who can't or won't carry out their orders immediately and to the best of their ability.

Sergeant Kelly is seemingly at home when things are at their worst. His sharp tactical mind somehow manages to infallibly direct squads of soldiers according to a brilliantly conceived battle plan. There are those who would call Sarge a machine, and they're not wrong.

He is at the top of the enlisted chain of command on the Mars Base (Marine HQ). Though he appears to be somewhat cold, he is very well respected for his duties and leadership. A career military man, he only expects the best from his men. He maintains a very fair treatment towards his men, giving good word to those who fulfill their duties and assigning slacking marines to the worst duties as punishment (such as being assigned to the solid waste facility).

Outside the military, Kelly appears to spend his personal time doing wildlife hunting. In one instance, he managed to hunt a grizzly bear with his double-barreled shotgun. Kelly appears to be very proud from this hunt as he has a head trophy of the same bear mounted on the wall in his office, as well as having the shotgun he used and a photo to commemorate the occasion.



Once the transferred Marine arrives to Mars, Kelly urgently orders him to report himself to Marine HQ where he was waiting. Kelly appears to be agitated when you first encounter him, as the first thing he says to you is: "Took your sweet time, marine?" and "I hope you can follow the sentry better than you followed orders so far."

Fortunately, it's your first day so he shrugs it off and gives you your first assignment (allowing you no time to settle in due to the lack of troops). You must locate a scientist who is missing and never showed to his post (Dr. Ishii, Delta labs researcher) and bring him safely back to HQ. Sergeant Kelly then sends you on your way with a Sentry Bot to guide you (he remarks that he hopes you follow the Sentry better than you've followed orders so far).

Not long after you locate the missing scientist, the demonic outbreak occurs killing (and possessing) Dr. Ishii and along with almost everyone on the entire base. Sergeant Kelly, now in Delta Labs, orders all remaining marines to head back to HQ for further orders. You are the only marine to arrive at HQ alive.

When you approach the communications monitor, Sergeant Kelly appears on the screen. He seems both surprised and relieved to see you and gives you your next set of orders: Link up with Bravo Team in order to send a distress call. His role in the game is significant: as he commands the Doomguy with orders different than those from Councilor Swann, he creates a conflict as to what the Doomguy should do. The question is whether or not to alert the fleet of the situation: Kelly wants reinforcements, Swann fears that the hordes of Hell will use it to invade Earth. In any case, it doesn't really matter, since if you don't contact the fleet, then Betruger does it himself.

After sending/canceling the transmission, the player is not contacted by Kelly again until he reaches Delta Labs. Kelly appears on a monitor in a recorded message and tells the player to meet him at Service Tunnel 1, but when the player gets there, Kelly is nowhere to be found (in fact, a trio of Cacodemons teleports in). After this, the player does not see or hear from Kelly again until the CPU Complex.

It is eventually revealed that Kelly has converted over to the demons' side. He ambushes Campbell and Swann in Delta Labs, gravely injuring Swann. Campbell chases after him, leaving Swann behind. The player encounters the wounded Swann, who warns him that Kelly has been turned. The player makes his way to the CPU complex where he finds Campbell, who has been ambushed and mortally wounded by Kelly. Before expiring, Campbell tells the player that Kelly has his gun. At this point, Kelly contacts the player and taunts him saying: "I killed that pathetic bodyguard, and now I shall kill you."

In the next level, the player comes face-to-face with Kelly, who has been transformed into a hideous tank-like monstrosity called Sabaoth. The player has no choice but to fight and kill his former commanding officer. After you defeat Sabaoth, you are rewarded with Campbell's BFG 9000.

Good or Evil?
The exact circumstances of Kelly's transformation are uncertain. Some affirm that Sergeant Kelly was working with Betruger and the demons since the beginning. This is substantiated by the fact that Kelly insisted in contacting Earth to bring the armada to Mars, maybe knowing that the fleet would be taken over by the demons.

However, a careful review of Master Sergeant Kelly's radio dialogue from the start of the invasion until the player reaches the comm tower strongly suggests he was never initially in league with Betruger, nor did he had any prior knowledge about Hell or the Delta Labs experiments before the invasion began. Kelly's statements and orders were concurrent with his command leadership experience, while having very limited intel on the opposing enemy forces. From Kelly's standpoint, he was dealing with a full-scale attack by an unknown enemy force. Nothing was known about their numbers and capabilities. All that was known to him amid the chaos was that he was quickly losing men, the units were cut off from one another and unable to regroup or fortify their positions, and most of the base was already in enemy hands.

Both Kelly and Swann had reasonable justifications in their dispute; Kelly urgently needed the reinforcements from Earth in order to ensure the base's security and engage a counteroffensive here in Mars, while Swann disagreed on the basis of not knowing what they were up against and keeping the threat quarantined to Mars until they could understand their foe. Had Kelly and Betruger been allies, Kelly would have been in position to send the distress call to Earth the instant the invasion began. Furthermore, Kelly never personally been to Hell, and informs the Marine later on that he finally discovered the source of the demonic invasion to be in the Delta Labs. Therefore, he would have no reason for being in league with Betruger before the invasion.

Bugs

 * In the French version of Doom 3, Sarge's "final warning" is in English.