A novel with a dream world and possibly time travel

Question

I read this adult fantasy/horror novel as a kid in the mid-90s in Bulgarian, but I'm 90% sure it was translated from the English language. I don't think it was written by an author I've heard since then, but I guess it must've done OK to have made its way to Bulgaria in the 90s.

Here's a few odds and ends I remember:

• Male main character, modern day setting, felt like the US.
• It involved a dream world of some kind. It was based on the idea that sometimes when you fly with an airplane over the sea, it looks like a vast plane of dry land instead (I didn't question this at the time, having never flown, but now that I've crossed the Atlantic a few times it feels like something the author fully made up). Someone figured you could travel to that dream world by getting a friend to see the empty ocean while you approach the ocean, so you'd see it too. You cross the empty land to get into the dream world.
• At some point, the protagonist is next to someone (a sidekick type character or a love interest). He can tell the other character is in the dreamworld because their eyes are moving in an REM sleep state.
• The dream world allowed for some time travel shenanigans. The protagonist has flashbacks to meeting a strange man stuck on his balcony when he was a child. It somehow transpires that he himself was that strange man.
• At some point the protagonist meets a nightmarish memory of an unborn child (aborted / miscarried, it was either a brother or his own son) with its lower jaw missing.
• The cover was green.

I think I enjoyed the book a fair amount when I first read it, but looking back at this description I'm not sure how much I'd enjoy it if I read it nowadays. Still, it's been eating at me for a while and it would be nice to see if anyone recognizes it.

Answer 1

Only Forward by Michael Marshall Smith.

The dream world is called Jeamland and the discovery of the plain that leads to Jeamland is described in the book as:

A long, long time ago, back when people still travelled between countries fairly regularly, there was this guy, on a plane. The man, whose name was Krats, was bored, whiling away the hours, and for want of anything better to do he leant over and looked out of the window. The plane was over the ocean at the time, way, high up, and he looked out and was struck by what he saw.It looked as though they were flying over some weird limitless mud flat, a featureless expanse of grey mottled by dips and low ridges. He knew they weren’t, of course, knew that it was just the ocean, but the longer he stared down, the harder that became to believe. He knew that the ridges and dips were actually waves frozen into apparent motionlessness by the height, and that their colour was dark metallic blue, but from up there it didn’t look like that. It looked like a plain.

Krats sees the plain when his friend Alkland is on the plane and sees the plain from the plane:

At the moment Krats’ friend was looking out of the window, Krats himself was in a store on the seafront. Suddenly he felt a strange sensation at the back of his mind, a kind of tickling. Thinking some acquaintance had snuck up behind him, he turned round, and he saw what Alkland was seeing now. The sea had disappeared.

He wandered out of the shop, mouth hanging open, and walked across the road to the beach. The ocean really had gone, and what was left was what he’d seen from the plane, a measureless expanse of … something, beneath a low, storm-like sky. Not even noticing that the beach and promenade were deserted, that all the summer tourists who’d been milling about when he’d walked to the store had vanished, he vaulted over the wall and went down to the beach. He walked out onto the plain, and he walked: and he found what he found.