"There's that strange signal again," Cortana said showing John the transmission.
"Think there's anything to it?"
"I'm curious more than anything."
"Keep monitoring and let me know if anything changes."

It had been an hour since their conversation about her condition and Cortana felt hopeful. There hadn't been any personality spikes and it seemed like the Chief was feeling optimistic as well.

"If we're going to hijack one of those covenant ships we're going to have to find out where they're landing first."
"I don't suppose you have a plan for that," he said, his tone playful.
"We could always asked nicely."
"Asking's not my strong suit."
Cortana laughed to herself. He didn't make quips often, but when did-he can genuinely be funny. I wish I weren't the only one who sees that side of him.

Cortana used to say things all the time to try and provoke him. Be honest Cortana. You were flirting. She smiled to herself. John never seemed to react except the corners of his mouth would curl upwards ever so slightly.

Only once had she heard him chuckle. It was such a surprise she didn't even realize what it was at first. John. I'd spend my days trying to get you to laugh if I could.

It had been on Earth during the first strike of the Covenant. Sargent Johnson had managed to get a tank for the next section of the campaign which meant things would go a lot faster and smoother.

Cortana had said to Johnson through the Chief's mic, "Thanks for the tank. He never gets me anything."
Johnson responded by sticking a cigar in his mouth and saying, "Oh. I know what the ladies like."

And there it was. A small rumble in his chest.

The Sarg. Out of all the people from their past, Cortana missed him the most. Maybe it was because he seemed to understand them the best.

"Don't let her go. Don't EVER let her go," he had said with his dying breath.

Did he know? Did he know something even I didn't at the time?

Cortana turned her attention fully back to her surroundings as the Chief came up to a terminus which he activated.
"It's a localized site cartographer. Hmmm. Okay. It says 'in service of Forerunner shield world. Designate Requiem.'"
"Requiem? At least we know where we are now."
"Let's see if can tell us what the Covenant are so interested in." As Cortana tried to access the system the map shut down and kicked her out.
"Huh."
"What?"
"I don't' know…it locked up."

It was strange that a map would suddenly lock up like that, but the whole planet was...weird. She and the Chief would need to figure out how to get the site cartographer back online. One more obstacle, Cortana thought.

As the Chief fought the Covenant they had stumbled on Cortana came across the signal which she had been tracking. What is this? She wondered. She continued to analyze. There is another possibility I hadn't considered. Perhaps it's human?

Cortana wouldn't tell her suspicions to the Chief until she could confirm them. Perhaps there's too much interference which is why the signal is getting lost. I wonder if the beams are contributing to the problem.

Immediately after the Chief had shut down the second beam the signal came through again clearer.
"Is that the same signal?" The Chief asked.
"Yes!" Relief poured through Cortana. Perhaps they could both get out of here sooner than she could have hoped. "Mayday Mayday! This is UNSC AI Cortana to Infinity. Please respond!" She waited, but nothing came through. "No response, but by the strength of that signal Infinity has to be close by. Maybe we can use the Cartographer to triangulate it's position. Put me in the system when we get back to it."

The Chief inserted her chip into the station and Cortana immediately got to work.

"I got it," Cortana said as the map showed the signal coming from the core of the planet. Odd. "Let me see if I can figure out a way to these coordinates that doesn't involve digging a really big hole." She continued to swipe through the system faster than even Master Chief could have guessed. "There's a terminus on the far side. We can portal to the planet's core from there." Cortana looked back the map with an uneasy feeling. It almost had seemed like something had manipulated the signal she had been looking at, but when she went and retraced all her steps she could find no evidence of anyone or anything meddling with the system.
"What?"
"I don't know…." Cortana said truthfully.
"If we have a shot at getting you back to Infinity, we're taking it."
If I can find no evidence of tampering perhaps it really was just the system taking a moment to respond. "Okay…" She said not unconvinced.
The Chief responded to her uneasiness with determination as he made an executive decision. He pulled her out and they began to make their way to the portal.

"What do you know about Infinity?" The Chief asked.
"Not much. She was supposed to massive but she was only in prototype when we left."
"Do you think Infinity picked up our signal from the Dawn? Or do you think they were already here?"
"It's possible they picked up our signal but with your luck I'd there's a good chance they were already here." Cortana paused as she read through the Covenant's Battle Net. "Chief the Battle Net is going crazy. They're ordering all units to converge on the tower."
"I guess we got their attention," the Chief said with a note of satisfaction in his voice.
Cortana sighed. "Time to gear up for some heavy fighting. Though with you, it's ALWAYS heavy fighting."

Heavy fighting proved to be a bit of an understatement as they came across a pair of Hunters which blocked their way to portal.

Cortana set to work trying to clear out some of the interference from the signal so she could play it for the Chief whenever he was done. It wasn't perfect, but it was enough to hear what they were saying.

Soon the Chief had disposed of both the beasts and took a plasma cannon from one of the alien corpses.
"While you were busy, I managed to clear up another transmission from Infinity," She said playing the snippet for the Chief to hear.
"Sounded like he said…artifact."
"I wonder if it has to do with whatever the Covenant are after."
"How much further is the terminus?"
"It should be just up this elevator," Cortana said.

Once they reached the top John put Cortana into the system. Forerunner technology, Cortana sighed in amazement. They had developed a whole transit system which would allow someone to portal to several locations inside the planet.
"Can you get us to Infinity?" The Chief asked.
"Hang on." Cortana couldn't understand what she was seeing. There were several power fluctuations as something began to materialize near them.
"Set a way point out of the tower," Chief said. Why won't the portal open? She was putting the request in correctly only the system wouldn't respond. "Cortana…"

Cortana turned to look at what had materialized near them. They looked like some kind of a AI, but she couldn't say for sure. Then suddenly a portal opened near them. "What the—"How did that happen? I wasn't actively in the system. Cortana didn't have time to think about it. "Quick! Into the portal!" With lighting quick reflexes The Chief pulled her chip and jumped into the portal.

"What was that?" The Chief said when they had made it safely through to the other side.
"I don't know. Some kind of defense AI? It's hard to tell without a closer look." The Chief walked through a door revealing the inside of Requiem. It was truly a feat of engineering that the planet could even exist. I could spend 30 years in the system and not know all of this places secrets.

"This is the core alright, but Infinity is definitely not here. That satellite in the center is broadcasting the ships signal like a relay."
"Can we use it to respond?"
The interference they'd been experiencing was due to beams that were coming off the satellite. They would have to shut them down to contact Infinity. Difficult, but not impossible. Once we figure out where Infinity is we can get home. There's still plenty of time for me. I'll make it.
"Opening a portal to first pylon. Pull me and let's go."