"Watch your left," Master Ikrit murmured, and Luke swung his lightsaber down to deflect Vader's latest assault.

Vader was implacable, fighting like an onslaught, and Luke was having trouble focusing on his training. He'd avoided a carbonite trap, and fought his way through part of the innards of Cloud City, but now he'd ended up trapped-

There!

His saber flicked, and he cut a gash in Vader's armour.

And, abruptly, the feel of the Force changed.

Dark fury simmered in the air like the feeling Luke had felt on a world he didn't even know the name of, a half-forgotten planet where Red Squadron had been based for four days and on the third a mighty thunderstorm had blown through.

This felt like the moment before the thunderstorm, when the air was heavy with more water than Luke had ever expected to see… heavy with the promise of a cataclysm.

Then that promise was fulfilled.

Vader battered Luke's lightsaber aside with a crash, and Luke did his very best to interpose it against the next attack. That saved his side, but left him hopelessly out of position – and a moment later, Vader severed Luke's blade hand at the wrist.

"Aagh!" Luke yelped, still trying to process exactly how quickly Vader had taken him apart, and for a moment the Force rose up around him like an overwhelming presence-

-then, they were gone, as Master Ikrit whisked them away into everywhere and everywhen.

Vader stared.

He looked at where his son had just evaporated.

Then he looked at his lightsaber.

Then he looked back at where his son had been. Before evaporating.

After frowning under his helmet for a long moment, he looked down, then peered over the side of the railing in case Luke had somehow fallen over while he wasn't looking.

Or if Luke's clothes had been drifting down while he wasn't looking.

There was no sign of where Luke had ended up.

There was also no sign of where Luke's clothes had ended up.

Try as he might, Vader couldn't work out what had happened. One moment he'd been fighting with his son, who'd been doing quite well all things considered even if he'd been showing a remarkable lack of blade skill, but then again it wasn't as if Obi-Wan had had long to teach the child.

He'd mostly been taking notes on how to teach Luke, and what to teach Luke.

Then, when he'd disarmed his son – literally, in fact – Luke had just… vanished, in a moment when the Force had pulsed with powerful warmth and light.

"Did I make a mistake the last time I tuned this?" he asked, looking at his lightsaber. "Because this is becoming a trend. Why does this keep happening? Why do Jedi keep vanishing!"

A sudden dire thought struck him.

"...is Obi-Wan still alive?" he asked.

AN:

An interquel to Backpack Bnuuy, asking what it looked like to Vader.