Complex sentence: Annabeth takes Jason to see a son of Hypnos (god of sleep) to try to find some of his memories through sleep, and the son of Hypnos explains to him the difference between the gods' Greek and Roman forms.
Split into simpler sentences: Annabeth takes Jason to see a son of Hypnos (god of sleep) to try to find some of his memories through sleep. The son of Hypnos explains to him the difference between the gods' Greek and Roman forms.