For last weeks' b7friday topic of teleport, 500 words set in season 4.
"I'm not going." Vila folded his arms and looked truculent. "That thing hates me."
Avon frowned at him "Don’t be ridiculous."
"Look, I've ended up in puddles, in the wrong place, with my arm wedged in a cliff, and once I didn't even go at all! I tell you, it doesn't like me."
"You're a fool."
"He's got a point," said Soolin. "Except that it's the other way round."
"And it seems to be catching," Avon said sourly. "Get ready, Vila."
Soolin gave him a cool and almost superior smile. "Wait. Tell me, Avon, how does the teleport work?"
He suppressed his irritation. "Quite simply. Two volumes of material, a person in one case and air in the other--" he paused, remembering the time it had not been, and hurriedly went on, "--change physical location via subspace."
"A person, yes. Have you ever teleported an inanimate object?"
"No," he said shortly. "We tried. It doesn’t work."
"Exactly. You found a working teleport on your previous ship and accepted that it functioned. This one is based on Seska technology and I'd assume it's similar. I knew the Seska." Soolin smirked. "They were experts in tele-ergonomics and energy transference. Telekinetics in other words."
Telekinetics. That was what Cally had used on the shadow planet, helped by the moondiscs. Avon compressed his lips, not wanting to think of Cally.
"The mind is obviously involved," Soolin continued, "and Vila's experience proves that."
"If that were so, then it wouldn't work on him at all," he said, taking refuge in the old insult game.
"Oh, very funny." Vila glared at Avon. "And it didn't, once."
"That's right, the first time the crew used the new one. I was there." Soolin turned to Vila. "As I said at the time, it was obvious why. You didn't trust it, did you, Vila?"
"Well, it hadn't been tested!"
"But it worked perfectly after Dayna called from Scorpio and you knew it was safe. I bet all your little mishaps were going to places you didn't want to." She put her head on one side. "Have you ever had a problem going back to safety?"
"No... yes, when I landed on my bum when we went to that sarcophagus thingy. We both did then, Avon and me. We couldn't get back to the Liberator because of that alien stopping us!" His eyes widened as he stared back at Soolin.
"Then Cally came to get us," Avon said slowly. "A telepath." He looked at Vila curiously. Soolin was right; the mind must indeed play some part, however unconscious. He felt intellectual shame that he hadn't realised it before. He frowned. Vila would be a liability, and possibly in danger of ending up inside a hillside or a wall unless he was relatively willing to go. It would be better to send someone with less imagination. "Very well. Dayna and Tarrant will go."
Vila would keep until there was a lock or the promise of riches to attract him.
The reference to something other than air being swapped during teleportation is from a previous story, Cavitation.