Complex sentence: She wakes up tied to a wheelchair, and Hugh explains that their sex has passed on a curse: an entity which can only be seen by those with the curse, and can take on the appearance of any person, will follow Jay at walking pace.
Split into simpler sentences: She wakes up tied to a wheelchair, and Hugh explains that their sex has passed on a curse. He informs her that an entity which can only be seen by those with the curse will follow Jay at walking pace.