Talk:Sea Dragon Leviathan/@comment-28728255-20181229233657/@comment-37094356-20190204230430

Ryley doesn't bring Kharaa to Earth, he got cured before he left remember

if you listen to the dialoge on the Aurora's page (i think that's where i found it...), the commander mentions Kharaa, meaning it was already on Earth or nearby planets. i don't know much about NS or BZ, but my theory is that after Kharaa made its way to Earth and created the monsters, Ryley told the commander about enzyme 42 and its curing abilities, leading to the events of Below Zero. and when Robin says to the SEL "this could save lives", she wasn't just talking about it could cure people, but it could also prevent the monster populations from growing.