APED: "dear doctor, i know well this news"

Dear Doctor, I know well this news
must come as something of a shock.
I know well, too, your fertile Muse
can render my just-finished talk,
or can, that is, if you should choose.
Please don't dwell upon the rocks
around which water's fury stews,
down at the base of Reichenbach.

The pigeonhole that's marked with M
contains all the police should need
-- if they should care, that is, to stem
the late professor's henchmen's greed --
My things? My brother sees to them.
Don't worry, Doctor. There's no need.
I know the cost will pain my friends.
You most of all. But take this seed:

Never doubt your heart, or brains.
Believe me, for I've taken stock.
You know my feelings are in chains.
I keep them so, and guard the lock.
But if there's one regret that pains --
no, no man who escaped the dock:
you'll never see the tear that stains
this note I wrote, at Reichenbach.