Sam walked over to the window and regarded the next room. As he did so, a lamp-like fixture focused on him and projected some sort of ray onto the boy. Sam froze. From behind him, an opening in the floor appeared and one of the shiny metallic blobs flowed out onto the floor. It flowed over to Sam and then up his leg.
Sam's body tensed for a few seconds, then relaxed. The strange light shining on him from the lamp switched off. Sam turned about towards the entrance and smiled an evil little smile. He couldn't have appeared more sinister even if light were shining up his nose. For effect, however, some unseen lamp was shining light up his nose.
Time to act sinister.
Sam waited for a minute or so and then he ran, shouting, out of the ship to his friends.
"There's this strange room that's like all white." Sam explained breathlessly. "And there's this window into another room with these puddles of metal. I was looking at them when they moved!"
"What sort of metal?" said an older kid named Tommy doubtfully.
"I dunno. It was all weird and shiny."
"So you're saying it was mercury?"
"I dunno, is that all shiny?"
“Then I guess it could be mercury.”
"Well," said Tommy in the smug tones of one who doesn't know what's going on, "it couldn't have been mercury because that's really heavy."
"So what was it?"
With the insight of someone who is practicing reverse psychology, Sam said "Let's head back home, this place gives me the creeps."
"And I want to tell my brother that I've been in a real live space ship!"