Stacey Branning gave birth to Kush’s son Arthur on EastEnders just before Christmas, but the birth has triggered deep-rooted psychological problems.

This week Stacey is in the grip of full postpartum psychosis, a condition during which sufferers have extreme mood swings and hallucinations. Stacey’s conviction that Arthur is the son of God led to a rooftop drama in which her and Arthur’s lives were endangered.

In a new exclusive BBC iPlayer featurette, fans are given a behind-the-scenes look at the making of Stacey’s storyline, including interviews with Lacey Turner (Stacey Branning), James Bye (Martin Fowler) and Dominic Treadwell-Collins (Executive Producer).

The featurette also explores the research behind the storyline and gives an insight into how Stacey’s story was created and brought to screen.

Watch Stacey Branning – On the Edge here at 8.30pm. immediately after the end of the episode.