The Vashta Nerada were closing in on River as the countdown continued. As the dark shadow from Anita's skeleton expanded and was nearing River's position she froze and a chill rose up her spine. The Vashta Nerada were still hungry and they sensed a perfect meal before them, it was their time to indulge...

"Hey, who turned out the lights?"

"You both should go now!"

Those voices echoing in her mind as she remembered the stories that were linked behind the phrases. She shuddered and looked at Anita's body lying in a heap on the varnished wooden floor. "I'm so sorry, Anita... I tried and I tried but, I failed to save you." She whispered to the motionless form. The last light on Anita's suit had stopped flickering and it died out, she was gone now, straight after one last apology...

The two sets of footsteps grew louder and louder as they marched down the corridor. River tilted her head towards the hole out of curiosity.

Through the square shaped hole, two human shaped shadows slowly emerged from the edge. River's heart was racing as she tried to stay alive long enough to think of a plan to save the Library and herself. Her eyes darted around the room as an idea struck her and she exhaled her nerves out deeply.

"I wish I could've saved you ..." She repeated to the now deceased Anita as the Vashta Nerada closed in. River rose to her feet and backed away from both the skeleton with its growing swarm and the hole that exposes her position.

River ran over to the computer and pressed a few of the keys. Her plan was beginning to fall into place. The computer screen read 'Platform Disabled' and the gravity platform in the middle of the floor disappeared. She stood in front of the gravity field and she exhaled heavily whilst taking one last look around the room... and she jumped.

As she fell, River felt the painful air resistance coursing through her body. But, the pain didn't matter as long as she made it to the core and stopped the Vashta Nerada. A blinding blue light surrounded her in every direction as she continued to plummet down deeper into the Library.

Her thoughts were racing through her mind almost as fast as she was falling. She felt her heart ache as the memories of her close colleagues dying were relaying over.

Now, her determination suddenly sky-rocketed and it was stronger than ever as this mission had to be completed in order to avenge her friends' deaths. "This ends here..." she confidently said.

She was nearing the bottom as the air resistance became weaker and weaker. The floor up above sealed and River was locked inside the Library core, safe from the Vashta Nerada and shut off from the rest of reality...

The speed which River was falling was slowing down and then, she stopped. River was floating a few inches above the ground. She regulated her balance as she eased herself out of the blue gravity field. Her feet gently touched down on the ground as she began to fix her curly locks that had been nudged out of place from the fall.

'Core Self-Destruct in 10:00 minutes.' The computerised voice notified.

Time was running out and River quickly scanned the room to make note of where everything was. The room was dark as there was minimal light and it was full of many metal machines, loose wires and computers and in the centre- the Library core. The core was a bright orange ball of energy and data that powered everything in the Library. Also, it was deadly if the protection shield around it was penetrated as the amount of data stored in and around the core would burn anyone who comes in contact with it and all of that data would be channelled through to aid in the fight to stop the Vashta Nerada.

She spotted the mainframe computer and typed in some details. The computer was at the foot of the core. The status still read '4,022 saved. No survivors.'

River wired up the computer to the core and to another machine which had various wires coming out of it. She was working quickly then she silently began to cry as she fiddled with various lose wires that she connected to the machine.

Her plan was to set the machine to download the 4,022 saved at the same moment that the Library core explodes so the blast can wipe out the Vashta Nerada which its data has been imputed into the database of the Library. However, the data from the core would course through the wires that River needs to connect when the countdown finishes resulting in her absorbing them and being burnt alive. She knew that the shock of the explosion would relay and end up killing her too, but it was the risk she had to take to save 4,022 lives. This was her biggest sacrifice, a painful death to save 4,022 others; her mind was set on the selfless side.

River walked over to the core and she opened up a panel that was on the side of the monitor projecting the shield. The panel was full of wires and switches, she altered them to change the settings and enter the exact moment at which the Vashta Nerada is to be erased.

"Okay... you can do this, River. You can do this." She mouthed those words of reassurance to herself.

Her hands were trembling as each second ticked away and the end was drawing nearer. She walked back to the machine down the hallway and she switched it on. Her gaze was fixed on the circuit of her doom.

'Core Self-Destruct in 5:00 minutes.'

River listened to the emotionless voice and she sighed. "Nearly time..." she raised her eyebrows as she exhaled in acceptance.

A faint sound chorused through the silence, it sounded like a struggling battle between the sound and the silence.

River turned her head as she tried to locate the source of the sound. It slowly became clearer and louder- it sounded like an engine... But, an engine to what?

River was puzzled, she also felt as if something or someone was behind her. She cautiously turned her head and looked behind her. She was startled and she gasped as a confused look riddled her face. Her curious green eyes looked past the machines and through the dim lighting.

"Hello, River."