Disclaimer: Diane Duane owns these characters, and is doing a far better job with them then I ever could. As evidenced by this little number.
"Actually, it's not that uncommon for wizards to have to figure the important things out on their own." Tom told Harry once. "Even as Seniors we don't always get a complete set of clear instructions."
Out if curiosity, Harry had asked as to the kinds of things he and Carl had learned over their wizardry careers. Carl, seated to Tom's left, suddenly choked on his coffee attempting what sounded like snorting laughter. When Harry and Tom had stared at him, he had deadpanned the word "brownies", which made no sense to Harry but did to Tom, if the shade of red he turned was any indication. Carl started laughing again. Harry had looked from one wizard to the other, feeling that familiar sense of being out of some sort of loop, until finally, Tom had turned his back on his partner and explained.
"Just after we were made advisories, I helped this charming older wizard who offered me some brownies as I was leaving. Being inexperienced and innocent (here another snort from Carl, which had Tom rolling his eyes again), well okay, just inexperienced, I couldn't think of any reason that might be a bad idea."
Tom paused, probably not for dramatic effect, but achieving one anyway.
"I came back to the house and ate a few while I worked on an article. Only to discover that these brownies had a "special" secret ingredient."
There's something about the way he emphasizes the word "special" that triggers certain memories in Harry's head from a time long forgotten. He had grown up in the 60's, after all, even if he hadn't engaged in all of the time's more interesting quirks.
"Oh no." he had whispered.
"Oh yes." Tom had replied.
"I came home from work" Carl picked up the story, leaning forward with a grin to do the Cheshire cat proud, "to find him sprawled on the living room floor, listening to Pink Floyd and babbling to our ceiling about how the meaning of life can be discovered by sending a jar of pickles through some hidden worldgate in Mexico. Terrified that he'd somehow swallowed alien poison, I sent a frantic message to the nearest healer."
"Bridget still makes fun of me every opportunity she gets." Tom had muttered, his expression ruthful. "As does this nutcase, although he was nice enough to hang around all night and make sure I didn't actually go to Mexico to implement that idea."
"I wasn't sure if I wanted go punch the guy for dosing you or laugh my head off, so I settled for babysitting as a worthy compromise."
A look had passed between them then, one of those looks that always makes him feel a little like he's seeing more then he ought to. With a sigh, Tom turned back to him.
"So to answer your original question, one of things we've learned is to never eat anything we're aren't completely sure is safe."
"A life lesson you passed on to Nita and Kit, I would hope."
Another look, this time slightly more sheepish. And THAT was story Harry just had to hear.