Advent Calender: Day 21

This is day 21 of the Advent calendar filled with 221Bs, brought to you by days_of_storm and me. We will post in rotation, so you get a 221B by me one day and one from her the next day, right up until Christmas.
Apart from the overall Christmasy theme we decided to refer to the previous 221B so that there will be a story in the end. Let's see how that works out.

A happy pre-Christmas season to all of you! :)

( Day 21 )

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