From time to time, our generous author will put out a special episode about Mrs Darcy's adventures available for all to see for no extra remuneration. The first of these came out just before Christmas 2010, the second came out on launch day, September 1st 2011 and the third one was released on Halloween 2011. The 2011 Christmas Special was a two-part epic; the first part is here and the second part is here. You can find the 2012 Jubilee Special here, and finally, here's the 2012 Christmas Special.
Very occasionally, Mrs Darcy will also pay a visit to other specially-selected franchises, such as this extraordinary adventure with Lord Likely (readers of a nervous disposition are reminded that this is Lord Likely we are talking about, so the filth quotient in this episode is slightly higher then usual). This piece was done for vvb32's 2011 Pemberley Ball, and this one was done as part of the Advent Calendar for the 2012 Get Writing conference.
But be warned. There may be spoilers!