HORATIO        If thou hast any sound or use of voice,

Speak to me.

If there be any good thing to be done

That may to thee do ease and grace to me,

Speak to me.

If thou art privy to thy country’s fate

Which happily foreknowing may avoid,

O, speak.

Or if thou hast uphoarded in thy life

Extorted treasure in the womb of earth –

For which they say your spirits oft walk in death –

Speak of it, stay and speak. (The cock crows. )        (1.1.127-138)

Horatio is doing his absolute best, covering every possible angle in his attempt to get the Ghost to speak: if thou hast any sound or use of voice, speak to me. If you have any kind of voice and can use it, please, say something! And, assuming you can speak: if there be any good thing to be done that may to thee do ease and grace to me, speak to me. It could be to our mutual advantage, just let me know: I’ll do what I can to help you—we all will (and implicit here in do ease is an offer to pray for the Ghost, to ease the pains of purgatory, perhaps?) and, as a work of charity, that will be a source of grace for Horatio and anyone else who prays for the Ghost too. Or, if thou art privy to thy country’s fate which happily foreknowing may avoid, o, speak! If you know something that we don’t about what the future holds for Denmark, your own realm, something terrible about to happen which, if we knew about it in advance, we could stop it—tell us! Please! Or—and he’s trying to think of everything: if thou has uphoarded in thy life extorted treasure in the womb of earth, if you’ve buried treasure somewhere, ill-gotten gains, and you’re now feeling guilty and you want us to dig it up—for which they say your spirits oft walk in death, that’s a really common cause of unquiet ghosts, or so I’ve heard, wanting their guilt to be assuaged, their consciences eased by the discovery and (implicitly) the return or redistribution of the wealth they had no business concealing: is that it? Speak of it, stay and speak! Pause a moment! Say something! Say anything! We’ll listen, and do what we can!

The cock crows. The effect is to break the spell on the audience, as much as anything else: suddenly the world of the play is bigger than what they can see on stage, all eyes on the Ghost, all ears on Horatio’s pleading, and there’s that simple, familiar, everyday sound from offstage. Day is coming. And the cock’s crow could be a cue—to the Ghost??