Hot off the BF website, it's the latest of their audio plays, The Chaos Pool in which the Fifth Doctor, human tracer companion Amy, and her sister and rival Zara close in on the last segment of the Key to Time. Actually the real star of this is Lalla Ward, who makes a triumphant return; it's not at first clear how or even if this will tie into the Gallifrey series of audios starring her, Louise Jameson and (in part) Mary Tamm, but it's all tied up satisfactorily at the end, including an explanation for Romana's regeneration in Destiny of the Daleks. Purists may object to the fate (or even the portrayal) of the Black and White Guardians, but (as I said in my review of The Destroyer of Delights) I saw it as a rather innovative move by Big Finish to reinvent two essentially rather boring stock characters. While I enjoyed the performances of Ciara Janson and Laura Doddington in the other Key 2 Time audios, this was the first to be recorded and they were still finding their way. The plot is suitably convoluted and enjoyable, though I didn't really grasp the point of the Teuthonians, and you couldn't really recommend it to anyone who hadn't already heard the first three Key 2 Time stories.