Sleeping Fire
They don't know she's here.
Not that the crew of the Spirit of Fire can really 'know' anything right now. They might dream. They might have nightmares. They might experience things that only an organic mind can sense. But they don't 'know.' They don't know of the ghost that makes her way through the ship. Like a wraith moving through a crypt, but with no intention of harming the living.
She's given up observing them. There's only so much interest one can get at staring at people in cryo. There's only so much human anatomy she can take. Even the males. Try as she might, she can't experience sexual stimulation at the sight of naked men on ice, so there goes one possible piece of entertainment for the next few decades. She finds herself going to Cutter and Anders every so often, but it's the exception rather than the rule.
Do they dream, the AI wonders? If so, what do they dream of? Think of? Satisfaction, knowing that spaceships of death have been denied to the Covenant? Sorrow, knowing that they'll likely never see their friends and family again? Guilt, for all those they failed to save? She's run programs based on their psychiatric profiles and come to a few conclusions, but unless she wakes them up, she can only theorize. And even then, she'd be hard pressed to get beyond "why did you wake me up" and "oh God, cryo burns!"
She smiles at this. If she sees the crew wake up, the joke will be on them. Or not. That joke got old years ago.
Moving on from cryo, she keeps moving. Drifting. Surveying. Sometimes she goes to the observation deck and watches the inky blackness of space. Like slipspace, but with a few points of light. Sometimes she goes to the bridge and stares at the tactical board, running simulations that play about as well as an RTS on a games console. Like everything, it's got old. There's nothing left to do. There's no more data to consume, and even if there was, would she do it? If the crew needs her in the near future (a big "if" admittedly), it would be best for her to be operational and not in the throes of Rampancy. On the other side of that "if" however, if she's doomed to spend her remaining years doing nothing, waiting for something, then maybe she can replace the nothing with something, even if it makes the second something come somewhat faster.
Or something. Or something else. There's probably some synonym in the hundreds of languages she's familiar with, but right now, she's past caring.
And so she waits. Waits in the dark. Waits in the cold. Watches and waits as the ship loses its spirit. Its fire. Waits in the knowledge that no phoenix will ever arise from the ashes.
For Serina, it's quite a depressing thought.