Final answer:
The Epidauria is a feast dedicated to Asclepius, the son of Apollo, celebrated as part of the Eleusinian Mysteries.
Step-by-step explanation:
The feast in honor of a son of Apollo that was included in the middle of a great ritual is known as the Epidauria. This festival was intercalated into the sequence of the Eleusinian Mysteries, a set of ancient Greek religious rituals. Specifically, the Epidauria occurred during a three-day period of rest and was dedicated to Asclepius, the son of Apollo and the god of medicine.
These Mysteries involved various rites, processions, and performances, gradually building towards significant climactic moments that conveyed secret knowledge and experiences to the initiates.