Jack meets Rassilon’s boundless gaze, and tries not to shiver despite himself. He reaches into Pond’s tweed coat and rolls his fingers on the hem, revealing the bug-wire he planted there during one of the many nights they slept together.
“You constructed the Transduction Barrier surrounding Gallifrey, yes? The Doctor, he…” Jack’s eyes flit down, despite himself, “…hinted to us about that, vaguely. Well here’s a little Christmas present- if you can buffer it enough and then loop it through the Barrier… you see the theory in play here.”
Rassilon takes the tiny listening device and holds it up to the light. A simple little thing really; just a small silver dot with a wire hanging out.
“Yes… in future I believe I might come to treasure this low-tech piece of nostalgia- thank you Captain Harkness. Your planting this listener on him is especially fortuitous for us now. But what will truly impress me is if this little thing still works. I will be gone only a short while, but nevertheless, please notify me of any change in his condition publicly over the comms. In return, I will share a secret with you that you may find entertaining…”
Jack inclines his head as the Time Lord leaves, and then it’s back to the gaslight vigil.