At this point, who should show up to spoil the party but… the ghost of Clytemnestra, Orestes's mother, whom he killed at the end of the previous play in the series (called Libation Bearers).
Clytemnestra calls out to the Furies, who are still sleeping inside the temple.
She says, "Hey, shake a leg will you! Get up! It's me, Clytemnestra! All the other dead people keep on disrespecting me; it must be because you haven't punished Orestes yet for killing me. Don't you remember all the sacrifices I made for you back when I was alive? Come on! Have at it!"
Still half-asleep, the Furies cry out from inside the temple (in Collard's translation): "Seize! Seize! / Seize! Seize! Put your mind to it!"
But that isn't very helpful. Clytemnestra wants them to help her, after all.
Finally, after telling the Furies off one more time, Clytemnestra's ghost floats offstage.
Now, still groggy, the Furies come out of the temple and array themselves in front of it.
The Furies form themselves into a Chorus and start dancing and singing. In their song, they complain about how Orestes got away from them; they blame Hermes, the god of trickery. (From Libation Bearers, Part II of the Oresteia trilogy, we already know that Orestes and Hermes are tight.)
In general, they think that the world is going to Hades in a hand basket because the young gods (like Hermes and Apollo) are turning against the older gods (the Furies themselves). Kid-gods these days, eh?
They think that Orestes needs to be punished for what he has done and blame Apollo for letting him escape.