'The Arc of Infinity', The Doctor's 1983 trip to Amsterdam, has to rank as one of the shows all-time lemons. What idiot would either want, least of all attempt, to create a sequel to such a disaster? Nev Fountain, that's who!
'Omega' came as the first of three homages to past villains in the run up to the 40th anniversary behemoth that was 'Zagreus' and was the most surprising as well as the most entertaining. It is also downright barking and features one of the most jaw-dropping end-of-episode cliffhangers ever. The last part is admittedly far too long (it is in truth a five part story, not a four parter), over-indulging its task of expanding on the past. Yet, as a couple of hours of audio entertainment for anyone saturated in the Who universe, 'Omega' is hard to beat. There is a great support cast, the music and sound design are top notch and Peter Davison is at his very best. It is, moreover, often extremely funny.
Though I've only given 'Omega' four stars, it is nonetheless one of a select group of stories from Big Finish's monthly Doctor Who range that I would not willingly be without. (See also: 'Phantasmagoria', 'The Church and the Crown', 'The Kingmaker', 'Year of the Pig', 'Magic Mousetrap', the six stories of 'Season 2002', 'Zagreus', the four stories of 'Season 2004', 'Other Lives' and 'Memory Lane'.) But be warned: if you're not at least partially aware of the two Omega stories on TV, you will miss a lot of the what the story's about. Great though 'Omega' is, it is unshamedly fan-centric.