Mesmerized, O & E, episode 7 “The Dream Continues On.”

One night E comes to O in a dream: she tells him to meet her in the woods – he should follow the stream until he comes to a gate, the portal to another world. There will be a 3 headed creature guarding the gate. O will have to convince the sentinel to let him pass, but he is susceptible to the charms of music. She will be waiting on the other side.