oh dear, I must say, I was afraid it would come to this. Dead fish are just so … so improper . But, whatever you say, Nell. You’re the professional. Cheerio.”
Fourteen minutes and one second later, Drake and Nell were once again at Plum River. Mary sat on her blanket, her picnic baskets all neatly packed. She dabbed her eyes with a hankie. “I suppose I’ll need to call everyone to cancel the picnic.”
Drake checked his watch. “That would be most premature, Ms. Pendleton.”
Mary looked confused. “But—but—you told me to pack …”
“Indeed we did,” said Drake. “Naturalist Nell?”
“Thank you, Detective Doyle.” Nell looked quite serious, as top-notch scientists often do. She began to pace. “You see, Ms. Pendleton, it was clear that something in Plum River was killing the fish—but what? And where was it coming from? Badger Creek gave us our first clue.”
“But what on earth does Badger Creek have to do with Plum River?” asked Mary.
“Everything, as it turns out,” replied Nell. “You see, Badger Creek empties into Plum River.”
“Of course,” said Mary. “Everyone knows that.”
“Downriver from Badger Creek,” continued Nell, “the fish were all dead, as you well know. But upriver from the creek, the fish were all alive, meaning that whatever was killing the fish was coming from Badger Creek.”
“So when we returned to Nature Headquarters,” Drake said, “Naturalist Nell tested the pH in the water samples we had collected.”
“Whatever do you mean?” Mary asked. “What is pH?”
“Ah, so glad you asked,” said Drake, pushing up his glasses with his finger. “Very simply, pH is a scale that tells you whether something is an acid, a base, or neutral. Tell me, Ms. Pendleton, have you ever taken a spoonful of vinegar?”
Mary shuddered. “Oh my, yes.”
“Vinegar is a type of acid,” said Drake. “So is lemon juice. Quite puckery. Now, tell me, have you ever nibbled on a piece of chalk? Not that I recommend it, mind you.”
“Oh my, no,” said Mary. “How uncivilized.”
“Chalk is a type of base, as is soap,” Drake explained. “Acids and bases are opposites.”
“Finally,” added Nell, “there are neutrals. Pure water is neutral, meaning it is neither an acid nor a base, but is in between. Most rivers that fish inhabit are neutral. Knowing this, I tested the pH levels in our three water samples—”
“While I,” said Drake, “using the latest in satellite technology, explored Badger Creek on the Internet. What we discovered was quite disturbing.”
“Disturbing?” asked Mary.
“About one mile up Badger Creek,” explained Drake, “is an industrial plant. I zoomed in on it with a satellite and observed that one of their tanks was leaking. Very simply, the runoff was emptying into Badger Creek and polluting the water.”
“I confirmed this with my pH tests,” said Nell. “Although the Badger Creek water looked quite normal, it was acidic. This acidic pollution poured out of Badger Creek into Plum River, killing all the fish downstream. Indeed, the water downstream tested acidic, while the water upstream from Badger Creek was neutral, as it should be.” Mary sniffed and dabbed her eyes with her hankie. “So tragic. I don’t suppose a picnic matters much when so many fish have perished.”
Drake patted her shoulder. “Cheer up, Ms. Pendleton. All is not lost.”
“Detective Doyle is right,” said Nell. “We’ll help you move your picnic upriver to where the fish are still quite happy.”
“You—you will?” asked Mary.
“And,” added Drake, “we’ll post signs directing everyone to your new location.”
Mary brightened. “Oh, you are ever so splendid! But—but—there is one thing that still troubles me. What about all the fish upriver, who are, even now, swimming to their deaths?”
“Ah,” said Nell. “We’ve already alerted the authorities. They’ll investigate immediately. No doubt, the factory will have