As jack awakes from something akin to what he feels to a deep slumber he feels deeply confused as only see darkness around him as his sight starts to switch to different types of vision
(A/N cant tell if xenomorphs can genuinely see or use echolocation or bioelectrical, so I'm going to take a liberty here and say they see in 5 types 'vision' echolocation through hissing and growling, bioelectrical signs emitted by living beings, regular light sight, UV vision and thermal vision)
"Ok confusing and headache inducing" as he starts to crawl around, he can begin to feel hunger this god awful hunger at a level he had never felt before it felt like his stomach had shrivelled from not eating for years and now it was begging to be fed.
"Ok, never thought I would be conscious for this period of my life cycle," as it's akin to being aware of the mind of an adult as an infant.
"Well, can't change fact time to start eating!" as he starts to wriggle his worm-like body, he unknowingly awoke what he was inside of. The poor human unfortunate enough to be the host began to wake up as the facehugger had fulfilled its purpose. It had lifelessly flopped off of the human's face. The release awakened the host from its comatose like state with a feeling of pain as its insides being eaten.
"What the hell, Pete! Joe! You guys, ok?!" as the human started to look around, it could see the terrain had been burnt and melted along with that it could make out two vague. Humanoid shapes in the distance as it started to move towards them, ignoring the pain it was feeling the human went towards its longtime companions only to see both of them not having any flesh remaining attached to their skulls.
"Oh god, I'm going to throw up" as the human started to feel nauseous, it tried to throw up. Still, no bile came out only blood." as the human stood over his friend's bodies in horror, it started to feel his chest constricting and pain like never felt before as he held his chest, something burst out with its terror-inducing screams and screeches, and that was the last thing the human known as 'bill' would ever know as he started seeing only black in its vision soon after before dying.
'Free at last, but I still feel hungry' jack or the chest-burster came out of the human's chest, ignoring the life he had just taken in his birth.
'Still, have two and a half more meals to go.' as the screeching horror started to pull its now long worm-like body out of the chest cavity of the human, it started to look at the 'meals' that it would soon consume for its growth.