Professor: ”…unless we reach Utopia.”

The Doctor: ”And Utopia is…?”

Professor: ”Every human knows of Utopia. Where have you been?”

The Doctor: ”Bit of a hermit.”

Professor: ”A hermit with friends?”

The Doctor: ”Hermits United. We meet up, every ten years, swap stories about caves.
It’s good fun for a hermit.”

Professor: ”…”

The Doctor:  ”So, um, Utopia?”