The Dawn drifted in space for a seemingly endless time to Cortana. Yet in the real scheme of time it was merely days; for a smart AI a minute was like a year in itself.

But then again, is time still working as before? Or is it distorted from the portal that divided the ship in half? She thought, as they continued drifting, so many questions were sitting unanswered in her mind, and that was one thing that AIs hated, not been able to answer any questions. The only thing that kept her sane in fact, was gazing at the unanimate body of the man that she had spent the most of her processing time with in a desperate battle; the Master Chief; Petty Officer John 117.

As she gazed upon his amazing physique, a garbled message echoed from the ship's half-working computer. That's strange. She thought, I thought I diverted all the half-ship's remaining power to the cryo-chamber. Whilst processing the mystery as to how the computer could have turned on by itself, she made her way through the computer systems and eventually reached the file that had just downloaded itself. She played the message.

"I followed you. I am Mendicant Bias; the monument to all my own sins." Cortana let out the computer-equivalent of a gasp, thinking of those terminals that they had read on the Ark; detailing the events and 'life' of a rampant AI. The AI was Mendicant Bias, and was tasked with defeating the Flood; yet the Gravemind proved too great a force and Bias turned sides, forcing the Forerunners into activating The Ring. Could Mendicant Bias really be here?

Quite possibly the best AI in the whole of human history decided to find out, she sifted through the ship's net, entering keywords such as Mendicant, and Bias. 
Your search returned no results.

-New Incoming Message, frequency unknown.

"It's no use. You can't find me. I can see you, but you can't see me." 

Cortana ran another search of the local disk drive, producing yet again no results. Another message downloaded. Cortana played it; this time the tone of voice had a deeper, more aggressive tone.

"He has defeated Fleets of thousands. He has consumed a galaxy of flesh and mind and bone!" It shouted in her mind, the volume causing her minor 'pain'. 

"Engines active."

What?! Cortana's AI core gave a lurch. There wasn't an engine on this ship!