River: Doctor, please listen to me. At least hear me.

The Doctor: Now, if I don’t come back, and I might not –

River: Doctor!

The Doctor: Go to the TARDIS. The Fast Return Protocol should be on. She'll take you home and shut herself down.

River: There has to be another way. Use the TARDIS. Use something! Save her, yes, but for God's sake, be sensible! [River tries to slap the Doctor, but he catches her wrist] How are you even doing that? I'm not really here.

The Doctor: You're always here to me. And I always listen. And I can always see you.

River: Then why didn't you speak to me?

The Doctor: Because I thought it would hurt too much.

River: I believe I could have coped.

The Doctor: No, I thought it would hurt me. And I was right [he kisses her passionately] Since no one in this room can see you, God knows how that looked. [Vastra, Jenny and Strax look awkwardly at each other] There is a time to live and a time to sleep. You are an echo, River, like Clara, like all of us in the end. My fault, I know. But you should have faded by now.

River: It's hard to leave when you haven't said goodbye.

The Doctor: Then tell me, because I don't know – how do I say it?

River: There's only one way I'd accept. If you ever loved me, say it like you're going to come back.
[The Doctor thinks for a moment]'

The Doctor: Well then...See you around, Professor River Song.

River: [smiles] Till the next time, Doctor.

The Doctor: Don't wait up.

River: Oh, and there’s one more thing.

The Doctor: Isn't there always?

River: I was mentally linked with Clara. If she's really dead, then how can I still be here?

The Doctor: Okay. How?

River: Spoilers! Goodbye, sweetie.