This is my first story so please review with massive criticism. I wrote this based on the situation the marines in the Sentinel Wall might have encountered. Enjoy.
Staff Sergeant Mack Thompson was leading his platoon of combat ready marines through the scary and ancient Sentinel Wall. Commander Keyes had given him orders to find a way through. Their current objective was to secure an LZ where Commander Keyes could land vehicles for their journey to the Library. Sentinels had been appearing to aid the marines and helped them combat the parasitic creatures that roamed the facility. Thompson activated a piston that allowed his men to drop into a room below them. The marines began sliding through the shaft with Thompson covering the rear. He turned to see the creatures began advancing towards him. Thompson quickly raised his weapon and provided cover fire for his men to continue. A human combat form snuck up on the Staff Sergeant and broke his spine with a whip from a tentacle protruding from the left arm. The piston closed but opened once more as the Flood began to drop down below.
Sergeant Castillo, leader of 3rd squad, was leading the marines through a hallway when all of a sudden a loud screeching echoed throughout the facility.
He shouted, "Marines!. Weapons up! Contacts are back!"
Sergeant Castillo looked to see Flood infected marines jumping out of vents and running towards the ill prepared marines. The grotesque creatures charged even as rotting flesh fell from the bodies they now controlled. 2 marines instantly raised their weapons to begin firing on the parasites. A shotgun blast consumed a combat form but another combat form jumped behind the marine and whipped him with its tentacle. The soldier's neck snapped from the blunt force leaving his SMG dual wielding friend to last a few seconds longer than he. A marine with 2 Magnums begin to fire wildly as infection forms were beginning to swarm their way through the hallways. Some marines panicked and tried to hide and hold out in a nearby shaft. They never came back out. A few Sentinels appeared but were destroyed quickly as they were no match for the weapons now used by the Flood. The Magnum marine was quickly swarmed under a never ending tidal wave of Infection Forms.
Sergeant Castillo shouted, "4th Squad! Proceed to the objective. We'll hold out as long as we can! Get it off! Get it off me!"
4th Squad began to wildly retreat further in to the Forerunner complex.
A Corporal, now in charge, shouted, "Suppressive fire! Suppressive fire!"
A trio of marines huddled back to back was making their last stand against the Flood. A marine equipped with a Shotgun was pushed away when a combat form jumped on one of his fellow squad mates. He sensed a rush of adrenaline and pumped 2 shells into an oncoming combat form. He quickly dispatched another but was overwhelmed by multiple combat forms. The last of the trio's SMG was no match for the fresh wave of Flood. The Corporal climbed into a nearby shaft with another marine. They both bottlenecked the two openings preparing to meet their inevitable end. A marine firing a Magnum was heard dying outside as the infection forms began to muffle his cries. The Corporal began shooting his Battle Rifle into countless combat forms but he and his partner were soon dead within seconds.
4th Squad's Sergeant Hayes rushed the men under his command as they dropped into the next room below. They were terrified of this new enemy they had just encountered.
Hayes firmly shouted, "We need to keep moving marines!"
The soldiers were instantly revitalized and ready for a fight. Hayes stepped onto a huge platform outside of the Sentinel Wall's interior. He ushered his men to move as the Flood began appearing. A Sentinel Enforcer escorted by a large number of Sentinels appeared and were providing cover fire for the now fleeing marines. The marines moved under the platform using a walkway. Stairs on the other side would get them out of there faster. The soldiers began to run and gun as the Flood closely pursued them. A marine pumped shells into 5 combat forms before they pushed him to the ground and made his deathbed.
"Go boys! I got your back," shouted Private Harris as he backpedaled onto a small ledge of the platform.
He fired his Battle Rifle on the combat firms and quickly regretted the last choice he ever made. Hayes was at the head of the group quickly gunning down combat forms. His men hopped into an open walkway and ran through to get to an attached platform. They sprinted as the Flood were combating Sentinels. A marine with an SMG was knocked to the floor and struck down as he rounded a corner as the rear of the group. PFC Melendez ran under this platform clutching his Rocket Launcher very closely. He ducked behind a small ditch as he struggled to reload his weapon. He heard a small thud behind him but was killed before he could see the combat form. Hayes ran into an open room overlooking the platform with the last of his marines. He activated a piston leading to another room below. A cocky Private hopped into a crevice and provided suppressing fire for his comrades. Hayes went down below and the piston returned to its resting place, sealing the Private off from an increased lifespan. Hayes could barely see 5 feet in front of him. This room was dense with a greenish fog. He gave the signal to advance when two of his men were quickly jumped and killed by combat forms. Hayes sprinted out of the trap with the last two of his men. They quickly adapted to maneuvering through the obstacle filled room. Hayes whispered, "Reyes. Establish me a secure connection with Commander Keyes."
The men ran across a glass bridge spanning into an identical room as the last but filled with Flood and Sentinels locked in a struggle. Reyes began to fumble with his COM link and the trio of marines quickly rushed past the distracted Combat forms onto yet another glass bridge and identical room. After reaching a dead end the marines decided to take a quick rest behind a small wall. Reyes handed Hayes the COM link. "Commander?"
"Go ahead Sergeant."
"Ma'am. We've encountered a new contact."
Hayes looked across the room and saw the faint lights of a Piston across from them. He also saw the shadows of Infection Forms and a few Combat forms emerging from a doorway.
"A new type of Covenant?"
Hayes and his men began to fire their weapons on the Flood.
"Negative ma'am! They are not Covenant."
Reyes shouted, "Cover that doorway!"
Commander Keyes waited for a response but none was available as the overwhelmed marines had become new victims for the Flood.