Elsewhere, Joseph Ballantine, professor and botanist, is hosting one of his famous experience parties.
That means hes serving some sort of weird mushroom tea that will get all his guests high.
Hes nothing if not endlessly curious.
Credit: Michael Parmelee/CBS
Attached to the bottle of Blue Angels is a note signed C.K.
It doesnt take long to rule her out though.
When they show up at her house to question her, Sherlock breaks in because he smells mushrooms.
Its gross, but you already knew that.
Charlottes death changes things.
Sherlock and Joan narrow down the list of labs and find one that Charlotte worked at.
That leads the detectives to an online pharmacy.
No one even knew it was Charlotte who owned the properties.
That leads Joan back to Austin Harper, who she feels they didnt look at closely enough.
Maybe Charlotte wasnt the real target; maybe they had dismissed Ballantine as the target too easily.
When Sherlock looks at the book published by Harper, he notices that his initials are A.C.H.
Thus, her original tattoo wasnt R.A.C.H.E., but rather A.C.H.
That gives the detective all they need to search Harpers lab and dig into his background.
He was actually legally married to Charlotte, having impulsively tied the knot when they were working with Ballantine.
He tried for years to get a divorce.
He synthesized the poison and killed her, while inadvertently killing Ballantine and his followers as well.
