One of the rare perks of being in the UK. It’s great film.
In the UK Descent ending, which is director Neil Marshall’s original and preferred conclusion, the vision of Juno shocks Sarah back into reality, a reality in which she’s still trapped in the cave and had never managed to escape. Sarah has clearly lost her mind, and sees a vision of her dead daughter in the cave with her, as the Crawlers look to be closing in. It’s a short extension, but it’s the difference between Sarah living and dying.