Half a kilometre in what?

In the middle of the night my darling husband says: "Oh, pretty far. About a kilometre in." I, being half asleep, did not clue in at first that he was talking in his sleep and probably rambling about nothing. Instead I thought I had missed some crutial part of an important conversation. So I woke up and said "I'm sorry WHAT? Half a kilometre into what?"

My husband just rolled over.

That's when I clued in. But I still wondered. What was he dreaming about? Halfway a kilometre in what? Half a kilometre into the corona of the sun? Half a kilometre into town? Half a kilometre into the haunted forest?

If I'd been more awake I would of tried to have a conversation with him (something that has worked in the past with my sister). My "What!?" probably jolted him out of the dream, but if I'd attempted to stay in the context of the dream I could learn what the dream was about. So the conversation might have gone like this:

"Oh, pretty far. About half a kilometre in."
"That is pretty far. Can you drive me?"
"Drive you? What's wrong with your ship?"
"The engine's broken."
"I can fix it for you. But you'd miss the eclipse."
"That's okay. I'll just try to jump start my space ship so I can fly into the sun's corona"
"Good. Carry on."

When I asked Adam about it in the morning he could not recall the incident at all. He thought it was cool that he talks in his sleep but wasn't able to tell me what half a kilometre in referred to. "I was probably giving someone directions," said he. He would be the type to dream about giving someone directions , while I would probably be the only one to dream about flying into the sun.