Latest of the Big Finish sequence of Companion Chronicles audios, this time bringing Mary Tamm to contemporary(ish) Norfolk to confront a somewhat sinister former astronaut turned cyborg aristocrat played by Madeleine Potter. Peter Anghelides hits a lot of good notes, the result being pretty faithful both to the Key to Time season and to the more steampunkish end of the Big Finish universe, and Tamm and Potter do it well.

I did notice a possible connection with Mary Tamm's Baltic homeland - the observatory whose nickname is the title of the story has a tame astronomer called Öpik (I think - might be 'Erpick' I suppose) who presumably commemorates the famous scientist from Estonia who lived out his declining decades in Northern Ireland, and whose grandson Lembit became a prominent Liberal Democrat. Or maybe it is just coincidence.