So little trust! John frowns sideways at Ianto as they walk, weighing up his scepticism.

"You didn't memorise all the officially recognised constellations in preparation for this?"

His expression softens after a moment, and he hesitates before giving an awkward shrug.

"Just -- trust me, I can give it a pretty good shot."

Assuming the map extends to any galaxies he knows. If it doesn't, well, that's more difficult. They picked him up, though. So they have to know where this is in relation to Pegasus, right? Right. Probably.