This first instalment juggles too many competing ideas, with no unifying focus. The titular “eternal dogfight” – a clash between two species with thinly sketched motivations – jostles for space alongside Alice’s emotional subplot (returning home to reconcile with her supposedly deceased mother, now mysteriously alive). Add to this a couple of additional underdeveloped companions, one whose ability to “consume” antagonists feels more gimmick than plot device, and a David Bowie-esque rockstar character who still hasn’t done anything, and the Doctor zipping about on jetpacks. The result is a chaotic sprawl.