Complex sentence: Tory--who suspected they were overheard--follows her there then talks her out of her plan, only to take the baby, knock her down, then eject her out of the airlock killing Cally.
Split into simpler sentences: Tory--who suspected they were overheard--follows her to the airlock. Tory talks her out of her plan, only to take the baby, knock her down, then eject her out of the airlock, killing Cally.