This is my first real foray into ACD Canon, and it's dedicated to MrsPencil, that wonderful poetess and expert on canon poems - if you've not yet read her poems then you should hurry away and do so...but please come back and read this afterwards :) Also, I must thank MrsPencil for reminding me of a certain word for handcuffs...Mrs P I'm sorry - I nicked it...
Disclaimer: Like BBC Sherlock, ACD canon characters are not mine either :(

'Twas Christmas day at the Workhouse,

But for Watson and Holmes there's no doubt

That mischief and treachery here was afoot,

It was time now to send in a scout.

~O~

Step forward one urchin called Wiggins,

Irregulars, leader of band,

He could enter the place and collect evidence

Using well practiced sleight of hand.

~O~

They waited in fog-shrouded alley

For their light-fingered friend to appear,

Hidden from reveller and villain alike,

And from singers of seasonal good cheer.

~O~

Watson with trusty revolver in hand

And beside him stood Holmes with his cane,

Shoulder to shoulder they awaited the fiend

Who used other's misfortune for gain.

~O~

Wiggins, fleet footed intruder,

Sped past with a hessian bag,

Tips his hat first to Holmes then to Watson,

Speeds on chased by angry old lag.

~O~

With a swing of his cane Holmes has downed him!

And Watson, he aims trusty gun.

The echo of footfalls grow closer,

Comes Lestrade of the Yard at the run.

~O~

He bends down and slaps on the derbies

As Wiggins returns with a grin.

Hands to Holmes the contents of the hessian bag,

Works for earning the wages of sin.

~O~

"Blackmailer" says Holmes "is now taken."

Workhouse manager he is quite shocked

But it's Christmas Day at the Workhouse,

He goes in, and the doors they are locked.