This is the best start to a finale since Matt Smith’s first series and is, for me, being on a par with both The Pandorica Opens and Bad Wolf - the latter of which sets the benchmark for finales in the new series so far. Danny, Clara and the Doctor’s tetchy dynamic throughout the series suddenly comes into full focus here, but with a clarity that feels very satisfying and rewards what has been a challenging theme not always executed smoothly. This episode delivers the payoff spectacularly: the volcano scene, Clara’s deception of the Doctor, the Doctor’s deception of Clara. It all fits together perfectly, forming a beautifully crafted piece of dramatic writing that feels darker than most Doctor Who - yet very rewarding.

When the story shifts to the Nethersphere, it offers a chilling science-fiction vision of what the afterlife could resemble - a notion thankfully overturned when revealed as a ploy by Missy, who, in a shocking twist, emerges as a new regeneration of the Master. The revelations here are plentiful: from the Nethersphere’s true purpose, to the dark water, and the horrific significance of the “three words” - each escalating tension.

Missy injects a curveball of bizarre fun into the mix, embodying a weird, wild reinvention of her character. At key moments, she upends the narrative, providing an enjoyably mad and comic counterpoint to the Twelfth Doctor, who serves as a straight-man.

This first part crackles with energy, pace, and mystery, and, despite some great stories since, is the first time it is firing on all cylinders since The Day of the Doctor. I can’t wait to see how this story concludes!