'It's a work in progress,' says Jodie Whittaker's new Doctor, having figured out a most tenuous plan to beat the baddie in her first adventure, 'but so's life, it'll be fine.' In the end she's the most dependable element of the new series of Who – which also marks Broadchurch creator Chris Chibnall's takeover from Steven Moffat as showrunner – permanently flustered but in command, with an accent which you might call regional (Yorkshire in this case, a move south from Peter Capaldi's Glaswegian) and a demeanour which says clowning, eccentric science teacher. If the jury's out on anything about the new series, it certainly isn't her.

Whittaker is the Doctor, as becomes clear within seconds of her arrival; a literal fall to earth, continuing from the point at which her TARDIS exploded at the end of the last episode (which happened nine and a half months ago, so casual viewers can be forgiven for feeling like they needed a recap). To be honest, any concerns about Chibnall taking over as showrunner – mostly instigated by his involvement with the decidedly lukewarm Who spin-off Torchwood way back when, rather than his serviceable episodes as writer on the series itself – are mitigated by the fact that everything seems fresh and intriguing.

Returning to the very first iteration of a Doctor Who cast from 1963's debut series, the supporting 'companion' cast is a pan-generational ensemble (Bradley Walsh, Tosin Cole, Mandip Gill), rather than the lone, wide-eyed young woman following a mysterious older man around which past versions of the new series have worn to the bone. There's a lot of potential in the group dynamic here, particularly from Walsh, a man of nearly 60 who's known as much for presenting roles as for acting, yet whose warmth and humour bring an inspired piece of age-blind casting.

The demands of requested spoiler-free reviews mean we can't go into great detail about the rest of the episode beyond a few vague points, but we will say that as well as the cast, other enjoyable aspects were Alec Roberts' (composer for Wonder Woman and The Meg) score, which surges with synthesised menace and an eventual sense of uplift which manages not to be corny; a menacing villain whose big reveal is commendably unpleasant; and a final action sequence rich in genuine tension. Chibnall's decision to add a proper cliffhanger ending – which will apparently be a feature of all ten episodes – also makes us doubly keen to return next week.

The city of Sheffield acts as almost an additional character, and the tone of this particular story borrows as much from Attack the Block (one of Whittaker's most prominent past roles) and Under the Skin as it does from established Who. In fact, it's the well-worn tonal holdovers from Moffat's and before him Russell T Davies' runs which jar the most; for example the Doctor's tough soliloquy-as-threat, which sounded striking when Christopher Eccleston first did it, before losing its novelty by the time David Tennant was done. That's a minor point, but it's an example of the established predictability which Chibnall's show feels like it's yearning to escape. Whittaker is a strong, comforting presence, and with the show's new Sunday night drama slot taking over from Saturday's pre-Strictly light entertainment scheduling, hopefully the stories her Doctor leads us through feel less need to cosset. It's a work in progress, but on this evidence it should be fine.

Episodes watched: one of eleven.

Doctor Who, Season 11 starts on BBC One, Sun 7 Oct, 6.45pm.