So, earlier today I was re-reading The Ruins of Gorlan. (Well, I actually just turned to a random chapter and started reading from there.) Then I saw Ulf's name! Sir Rodney mentioned him. So, of course, I had to write a fanfiction about it!
By the way, I'm just warning you that this fanfiction has EXTREME OOC-Ness. If you feel angered by this, feel free to leave a flame. I'll enjoy laughing at you.

Hal looked around the small structure, wondering whether he was missing someone. Then it struck him. "Where's Wulf?" He asked the other members of the Heron brotherband.

The one that Hal had assumed to be Ulf yelled. "Here! You going blind, Hal?"

Hal shook his head. "Where's Ulf, then?"

Then Ulf came stumbling through the door of the structure, looking extremely bewildered and tired.

Hal studied him. "Where have you been, Ulf?"

"I was just—" He began, but Hal cut him off.

"You were with the Sharks, weren't you? I knew it!" Hal turned to the rest of the brotherband, who were all looking bewildered at Hal's sudden accusation. "Ulf's been telling the Sharks all of our secrets!"

"Um, Hal, I actually wasn't." Ulf said.

"Yeah, Hal, that was a pretty wild accusation." Jesper said.

Hal gasped. "Gorlog's beard!" He cursed. "It wasn't Ulf. It was-" Hal let out a loud sob. "Jesper ."

"What?" Jesper yelled, his voice rising an octave. "Why would I tell the Sharks our secrets?"

"Speaking of which, what secrets do we even have?" Stig added.

Hal started trembling violently. "My entire brotherband is turning against me." He said quietly.

"We aren't all turning against you, Hal…" Stig said, wondering why his friend was acting like such a nutjob.

"Yes you are." Hal gasped. "Ulf is against us. In the future, when Zavac steals the Andomel from us, he falls asleep so that Zavac has it easy!"

The entire brotherband was dumbfounded. Not only was their leader making wild accusations, he was also accusing people of doing things in the distant future.

"Calm down, Hal." Ulf said, not appreciating the fact that Hal had said that he was the one who would fall asleep.

Hal turned to face Ulf. "If you aren't a traitor, then where were you just now?"

The rest of the brotherband turned to face Ulf. "Yeah. Where were you?" Wulf said.

Ulf looked at the ground. " I got a job."

The entire brotherband gasped, Hal the loudest of all. "YOU DID BETRAY US! YOU'RE GIVING INFORMATION TO THE ENEMY!" Hal yelled in Ulf's face.

The brotherband gasped again. "Why would you do such a thing? Wulf said.

"I didn't give any information to the "enemy," as you put it." Ulf said.

"What were you doing, then?" Stefan said in an accusatory tone.

"Umm…I got a job."

"You said that already!" Stig yelled, preparing to pounce on Ulf for betraying them.

"What did this job involve?" Wulf asked.

"Horses." Ulf said, bracing himself for more accusing words.

"I bet they were the horses of the enemy." Hal said, eyeing Ulf suspiciously.

"I bet that he was using them to set a trap for the rest of us." Jesper said.

I bet that they're outside right now, just waiting for us." Stig added.

"No…they aren't" Ulf said, wondering when, exactly, his entire brotherband had gone insane.

"Where are they, then?" Wulf asked.

"Yeah! What are you hiding from us?" Stig yelled.

Ulf clenched his hands, unable to handle any more accusations. "They're in Araluen! I got a job at the stables in Araluen!"

"Oh." Stig said cheerfully. "Glad to see that you're not a traitor. He patted Ulf on the shoulder, and the rest of the brotherband repeated the gesture. Except for Hal.

"What?" He yelled. "I'm half Araluen and everyone gives me trouble about it my entire life, but Ulf can just up and gat a job there, and no one has any objections?"

"Well, you apparently do." Wulf said quietly.

Hal glared at Wulf. He narrowed his eyes. "You are so going to betray us all."

"What?" Wulf asked, looking around at the other members of the brotherband for an explanation.

Hal turned to Ulf. "And your new job is going to get us all killed if you go back again."

Ulf looked just as confused as Wulf.

"What are you saying, Hal?" Ulf and Wulf asked at the same time, for once too nervous to argue.

"I'm saying that you two will be the destruction of us all."

Stig looked at his best friend, who had clearly gone insane from lack of water or something. "I think we need to go dump him in the river." Stig said, dead serious.

The brotherband happily obliged.

Unfortunately, when they dumped Hal into the river, Hal hit his head on a rock and nearly drowned. When they finally managed to fish him out and take him to a medical-person, they discovered that Hal would be fine, once he stopped being unconscious. It took about five seconds for this to happen. There was one side affect from the incident, however.

When Hal woke up, he had no memory of the event.

He was also mostly back to normal.

Also, Ulf eventually, quit his job at the Araluen stables, as it was proving tiresome to teleport back and forth between Skandia and Araluen. And he also didn't want to trigger another of Hal's episodes.

Which is why it was never mentioned in the books.