From the introduction:
Zeus is an amorous fellow. One morning he was looking down fromthe heights of Olympos and happened to notice something in a remote corner of Hellas called Locrisia. There he spied a beautiful nymph sunning herself on a hillside. He looked for her again every dav after that, but he never saw her again. After several weeks he became re ally curious and decided to do something about it. Being Zeus, his intentions towards the nymph are fairly easy to guess. Since he does not like to lower himself to wanderingaround among men unless absolutely necessary, he will recruit the characters to do his legwork for him. He will give one ofthem a mirror with which to communicate with him (only if they find the nymph, otherwise he would rather not be bothered), and set them down on the borders of Locrisia. They are to locate the nymph, inform her of Isis interest, and then summon him whether she is interested or not.