"No, no, I'm confident we replicated the late Dr Jekyll's formula exactly," the alchemist contradicted. "The reconstructed notes were pretty clear, once we corrected for the impurity in the salt. It simply does not work as intended." She peered up at the reddened face of her client. "At least, the formula does not 'sever people from their morality', as you put it."
"Then what does it do!" he burst out.
"Cause a transformation!" the alchemist said cheerfully. "Very substantial ones in some cases."
"What the devil do you mean some cases?" her client spluttered angrily.
She sighed. It was a crying shame that people rich enough to fund questionable alchemical research never seemed to have any love for the subject. "Well, none of the mice seemed to change at all. But most of the cats became much, much bigger. And our first human volunteer turned into a dragon!"
The man's eyes bulged in bewildered incomprehension. "What?!"
"Yes, unfortunately she did make off with an entire bottle of serum and will no longer return our calls, but I'm sure she'll be back when she runs out."
There was more spluttering and more eye-bulging. Another day, another disappointed financier that would not get their money back. "How is that even possible! That isn't even close to what the serum was designed for! Nowhere near the effect it had on Jekyll!"
"Mm, yes," the alchemist hummed with a wry smile. "My current theory is that your Dr Jekyll wasn't a very nice man." She turned her back on him with a swoosh of her soot-stained lab coat. "Now if you'll excuse me, I have a paper to write! My results will have far more credibility in the occult community now that I didn't find what you were looking for."
[Inspired by @alithographica's tags on this post.]