"Artie! Doctor! Dinner!" Clara called out the back door.
"Come on, Artie, you get to do the dishes tonight!" Angie added.
"Angie, would you please get the dinner on the table while I go retrieve your brother and the Doctor? Oh, and get that, will you," Clara added, as the phone rang.
She quickly crossed the yard to the old garden shed. "Doctor? Artie? Are you both still in there?"
"Clara, come see!" Artie called excitedly.
Clara shuddered inwardly at the site of all the jars full of different creepy-crawlies lined up on the potting bench. "Well, isn't this er…interesting," she said dubiously.
"Clara," the Doctor said seriously, "I'll have you know that this is quite an impressive collection for a fellow of Artie's age to have amassed."
"I think I've got everything you can find in this neighborhood," Artie informed her proudly.
"Really. I had no idea how many kinds of bugs lived around here." She drew in a deep, steadying breath as she felt a phantom itch begin between her shoulder blades just from watching the various small creatures crawling around inside their jars. "Well, anyway, your dinner is ready. Go on inside and wash your hands. With hot water and lots of soap." Clara smiled fondly as her young charge ran off back to the house.
"Care you join us, Doctor? I'm afraid George isn't home yet. Doctor?"
"Clara," he replied slowly, looking up from one of the jars he'd been studying. "There's something here that shouldn't be."
"What, you mean like one of those Oriental beetle things they mention on the news occasionally?'
"No. Like something from another planet."
Clara bit her lip in consternation. "Is it…could we have brought it back somehow? Like, stuck to our shoes or something?"
"No," the Doctor reassured her. "The TARDIS has strict decontamination protocols. No hitchhikers allowed."
She sighed softly, relieved of the sudden rapid stream of visions of intergalactic critters taking up residence in her clothes or worse, her hair. "Then, how?"
"Oh, any number of ways really. Could have hitched a lift on a meteorite or asteroid that crashed to Earth, one of your own space shuttles, or any of the myriad visitors that wander around all the time that you lot never notice."
"How could we not notice aliens walking around?" she asked quizzically.
He merely raised an eyebrow.
"Riiiight. OK then…is it a good alien, or a bad alien?"