References to What's on the Other Side of the Transcend

There are hints, but no more, that there might be something beyond the Powers that exist in the Transcend. (Note: it's a bit odd to be speaking of "beyond the transcend" when "Beyond" is below the Transcend...)

I found the following quotes from A Fire Upon the Deep; being situated in the Slow Zone, there's really nothing relevant in A Deepness in the Sky or "The Blabber" and while there is some movement in the Zones noted in The Children of the Sky it doesn't touch on the Transcend.

The artifact's twisting evolution slowed. The light hung at the pale edge of blue. Pham's eyes opened. His head turned toward her. "The Riders' Myth is real, Ravna." His voice was distant. She heard the whisper of a laugh. "The Riders should know, I guess. They learned the last time. There are Things that don't like the Blight. Things my Old One only guessed at...."

Powers beyond the Powers? Ravna sank to the floor. The display on her wrist glowed up at here. Less than forty-five hours left.

_{A Fire Upon the Deep, chapter 41}

The man's face went blank, Pham Nuwen almost disappearing behind the other programs at work in his mind. Then, "I'm... focusing Countermeasure. I see now, Countermeasure, what it is.... It was designed by something beyond the Powers. Maybe there are Cloud People, maybe this is signaling them. Or maybe what it's just done is like an insect bite, something that will cause a much greater reaction. The Bottom of the Beyond has just receded, like the waterline before a tsunami." The Countermeasure glared red-orange, its arcs and barbs embracing Pham more tightly than before. "A-and now that we've bootstrapped to a decent Zone... things can really happen. Oh, the ghost of Old One is amused. Seeing beyond the Powers was almost worth dying for."

_ibid

So there may be something, and it's possible that the Old One knew something but that information wasn't given to Pham.

The "Riders' Myth" referred to by Pham doesn't provide any more concrete information:

"Not many have. Not that it's a secret; it's just we don't make much of it. It comes close to being religion, but one we don't proselytize. Four or five billion years ago, Someone built the first skrodes and raised the first Riders to sentience. That much is verified fact. The Myth is that something destroyed our Creator and all its works.... A catastrophe so great that from this distance it is not even understood as an act of mind."

_{A Fire Upon the Deep, chapter 25}