📚 Yes, if you're reading Percy Jackson books for the first time, I suggest reading Chalice of the Gods and Wrath of the Triple Goddess after Heroes of Olympus, before reading Trials of Apollo. The Senior Year Adventure books go chronologically between Heroes of Olympus and Trials of Apollo. This is contrary to my usual advice of reading books in publishing order. The reason for the exception is that they're not really prequels to Trials of Apollo. The Senior Year Adventures directly continue Percy's story, whereas Trials of Apollo is more of a spin off.