| Spoiler warning!|
This article contains major plot details or explains info that the player may want to find out on their own.
Jeff Murray is one of the bosses of Subterrain. He is fought in Basement 1 of Murray Mansion, but can only be accessed after Albert West has MPO purified. Due to the difficulty of the fight, dying in the fight with permadeath enabled will not delete your save files.  This also applies to the next fight.
Upon meeting West again, Murray offers him the chance to join him. Regardless of the choice, however, a battle ensues. Accepting the offer has West lament about how all of his efforts were for Jennifer West, but Murray, claiming to be a god, says that she is his and decides to eliminate Albert.
The FightEditThe fight with Murray is difficult and very fast-paced. You should bring the best equipment that you can afford to make, if not the very best available, including some windroid X. You should also avoid completely overheating your weapons, because Murray will give you few opportunities to pick it back up, let alone re-equip it. Shields do not appear to affect any of Murray's attacks; this may be a glitch, but it may be worth shielding in case it still negates fractures and bleeding, both of which Murray is fully capable of inflicting. A fracture could easily lead to an immediate death.
For maximum mobility, a Battle Suit MK III and several windroid Xs are highly recommended. Melee weapons and shotguns are not recommended due to all of Murray's close combat attacks, although they may be useful during his laser attack if you opt to circle him. A fully upgraded pistol is recommended for its accuracy, range, and high damage when considering critical hits. A second such pistol will be useful for letting the first cool off while still maintaining damage. Complete Medical Kits are highly recommended in order to patch up any damage that Murray may inflict during the battle. Weaker medical kits are not recommended since, except for the most basic one, they all require the same amount of blood and tissue extract, and the most basic one heals too slowly for such a fast-paced battle. Assuming you are using XL power packs, one is plenty if you don't miss too many shots, but the Battle suit has plenty of item slots, so keeping some spare is still a good idea.
Murray starts by showing off an explosive force that he can release. This first one will not hurt you, since it's during a cutscene, but he will do this whenever his HP falls by a certain amount, and it can be fatal. It should be avoided at all costs. In addition, each time he does this, his speed increases slightly and he may start using a new attack; these will be referred to as "phases". Murray prioritizes changing phases over attacking, so hitting a phase's HP threshold will cancel any of Murray's attacks that are in progress.
Initially, Murray will only attack with punches and a small lunge forward, not unlike the punches of Muscled Mutants. Of course, his punches hurt just as much, if not more, and are just as capable of fracturing West. Even at the beginning, Murray's speed is slightly higher than West's walking speed with a 130% speed boost, so either running or a windroid is recommended.
After a few phases, Murray will begin using a quick body slam. It has a short wind-up where Murray appears to double over, after which he body slams extremely quickly in West's general direction. The distance that he covers with the body slam is initially somewhat short (about half of the room's length), but increases with each phase as well. The body slam deals a large amount of damage, but is very linear, so a quick side-step or hiding behind an obstacle may help to avoid the damage.
After a few more phases, Murray's speed will begin to match West's top speed (running with windroid X applied and a Battle Suit MK III worn), so keeping yourself topped off is imperative. His next available attack is a drill-like movement. After a few seconds of preparation, where Murray seems to take a deep breath, he will move extremely quickly in West's direction, with his arms flailing about in a drill-like fashion. This attack covers a lot of ground, can easily cross the entire room's length, can turn rather well, and can hit multiple times. Hiding behind one of the obstacles can stop him for a small time, but he will quickly start moving around it. However, with a little luck and timing, the entire attack can be avoided by circling the obstacle while he tries to hit you. If it hits even once, Murray will likely be right in West's face, at which point he can easily land a punch. If you aren't near full HP before this happens, it can easily be fatal.
The final attack that Murray gains is a laser. The attack is easily indicated by two of Murray's hands glowing red as he slowly brings them together. The laser doesn't deal much damage, but lasts for a while, slows West greatly when it hits, and rotates quickly until it is very near West. However, it cannot penetrate the obstacles in the room. Since Murray rotates slower when West is closer, you can attempt to circle Murray while hitting him, since he will be standing still. Messing this up can result in a lot of lost HP, though.
By the last few phases, Murray will be fast enough to easily catch up to West. To avoid dying to his variety of attacks, constantly healing up even small damage is recommended, and a windroid X should always be active. Murray's attacks also contaminate West slightly, but you would likely die from all the hits it would take to make it significant.
This battle essentially boils down to simple hit-and-run tactics. The safest option is to constantly run away from Murray, hopefully with a windroid X active, while also firing at him. Since you'll be aiming at him, you should be able to see his attack animations most of the time, and therefore be able to act accordingly. Running around the perimeter of the arena is the simplest and largest path to avoid most of his attacks while still being near the obstacles to use as cover. Prioritize staying alive over damaging him, because, compared to normal enemies, he can kill you very quickly.
If your HP falls to around 70%, consider using a medical kit. It's important to remember that it still takes time for the actual healing to occur, so you may take more damage during that time. Note that, if you are hit while applying an item like a medical kit, the process will be stopped and the item consumed, so only use a medical kit when you are not in danger of being hit within the next few seconds.
Try to keep all of your supplies in your suit's quick item slots, because Murray's speed will rarely give you a chance to navigate your inventory. Remember to shield whenever possible and whenever he seems ready to attack to avoid fractures.