It was official, Dipper thought as he watched the newcomer struggle to shelve some product Grunkle Stan had tasked him with restocking and glare daggers at his tourniquet-clad arm for the fifth time that hour.
William Nemo the Third, Esquire (as he had briefly demanded the twins call him before exasperatedly calling off an excited Mabel who repeated it 20 consecutive times in an increasingly outrageous British accent) was hiding something.
The deertaur absentmindedly scratched the soft velvet of one of his long ears as he gazed down at the increasingly full pages of the small evidence journal he'd been keeping over the past few days, documenting Will's odd behaviours and quirks.
And hoooo boy, did he ever have a lot of them.
For one thing, his clothes. They were immaculate, which by itself could just have been taken as a sign of caring about his appearance, except he always wore the same suit. The exact same suit. Every day. Dipper had yet to see him take it off, and, in fact, one night when he'd been curious he peeked inside the makeshift bedroom they'd hurriedly set up for him and witnessed the bizarre spectacle of Will lying ramrod-straight on his bed, covers untouched, his suit still very much in place complete with his small black eyepatch resting comfortably over his right eye as always, and apparently deeply asleep
Then, of course, there was the complete lack of surprise at the various…changes the members of the household had undergone. He'd laughed uproariously at Soos' booming voice and warped appearance and proceeded to rearrange his limbs into a truly Lovecraftian configuration, much to the handyman's delight (and the general public's utter terror), had spent hours up on the roof with Grunkle Stan the other night talking about…something, and, worst of all, had helped Wendy in the shop yesterday for like, two hours. Straight. This was clearly an act of psychological warfare.
Finally, though, and perhaps strangest of all…
Will knew things.
Things he shouldn't have possibly been able to know, given his status as complete and utter stranger. He knew about Dipper's birthmark, teasing him casually about it one afternoon while he was sweeping the floor (Grunkle Stan insisted on keeping the Shack clean despite the flow of customers being depressingly low as the town's supernatural population grew). He knew about Gideon, claiming to have 'tangoed with that lovesick midget one too many times for his taste'.
Plus there was the matter of his knowing the name of the enchanted stream that had started all this insanity, despite never reading or even touching the journal and claiming never to have gone near the place.
There was no doubt about it. Something was going on with Will.
He just wished he knew what.
Closing his evidence journal with a frustrated snap, Dipper ventured out into the gift shop as nonchalantly as possible. Will turned, abandoning his shelving efforts for the moment, his ever-present catlike grin affixed firmly in place upon his face.
"Glad you finally decided to come out," he said casually, setting the offending box on the nearby counter. "I could use your help."
Dipper started, an embarrassed blush rising. "Y-you knew?" Will cackled in amusement.
"Deer feet aren't exactly subtle, kid." He gestured to the box. "But they do mean you'll make an excellent ladder."
"…Ladder?" Dipper tilted his head in equal parts confusion and trepidation.
"Sure!" He stabbed his finger to the wall. "Prop your forehooves up there."
Dipper complied, albeit warily, and soon found himself in a very awkward position. Grabbing the shelf for extra balance, he turned his head in Will's general direction. "OK, forehooves propped," he called, slightly aggravated. "What do I do now?"
"Hold still," the answer came a moment later from right behind him, and before he could do anything, his rear legs threatened to buckle under a new, unexpected weight. Bill laughed giddily, teetering unsteadily as he clambered up the deertaur's back, box in hand.
"Are you INSANE?" Dipper yelped as Will's heel dug into his back.
"You should already know the answer to that question, Pine Tree!" he called down, still cackling madly. With a triumphant cry, the box was placed, and he raised his one good hand in an exultant gesture of victory.
This, of course, meant he had nothing to keep him upright on Dipper's back.
The impromptu tower swayed and fell, the two of them toppling into a messy heap. Will giggled breathily.
"Let's do that again!"
"No," Dipper said flatly, shoving the teen off of him with a grunt and rising to his feet. Ugh, he was going to have foot-shaped bruises all over his back, he just knew it.
"Ahh, you're no fun, kid." He grinned. "Besides, I might need you again!"
"What, as your personal stepping stool?"
"Sure!" He picked himself up, adjusting his tourniquet and wincing slightly as he did so. "We could even strike a deal! You help me out in the shop, and in return I'll help you look for that cure you're so eager to find." He extended a hand with a flourish. "Whaddaya say, kid?"
Dipper paused, considering. On the one hand, he did need all the help he could get researching a cure for the water's enchantment; there wasn't anything in the book on a possible cure, and the author's writings on the stream stopped abruptly halfway through the entry.
On the other hand, though…
He looked at the hand, and at its owner's expectant grin, and felt a chill run up his spine. There was something about this, something he couldn't quite put his finger on, that felt familiar. Familiar, and very troubling.
Something told him that Will Nemo could not be trusted.
Slowly, he shook his head. "I'll pass," he said, keeping his voice casual. Will pouted.
"Aw. We woulda made a great team, you and I!" He shrugged. "Well, if you ever change your mind, I'll be here for you." He leaned in, waggling his eyebrows. "Ready to make a deeeeeeal!" With that he turned back to his shelving, laughing at some joke that only he knew the punchline to.
Dipper stood there for a moment longer, then walked away, mind whirring with thought. He'd heard that somewhere, he knew he had. It was right on the tip of his tongue, if he could only just –
His eyes widened as he thought back to something Will had said just moments prior.
"You should already know the answer to that question, Pine Tree!"
Pine Tree.
Only one person had ever called him that.
Or one demon, rather.
The notebook dropped from his trembling hands as he turned, slowly, to look at the man in the gift shop, cheerfully humming some unknown tune to himself as he struggled to lift a heavy package with only one arm.
The knowledge. The eye patch. Now that he thought about it, his laugh was exactly as he remembered it too, high-pitched and nasal, making you feel as if you'd lost a game you didn't know you were playing.
He knew what William Nemo the Third, Esquire was hiding.
Slowly, then gaining speed, Dipper took off out the front door towards the lake, where he knew Mabel would be at this time of day.
And inside the gift shop, Bill watched him go, grinning.
Finally.