Upcoming episodes will see Kat discover that her grandmother Mo Harris has accepted Harry's cash on her behalf, which sends her on another downward spiral and leads to her taking an overdose.
Alfie proves to be Kat's saviour as he realises what she has done and races to her rescue, calling an ambulance so that she can be rushed to hospital.
EastEnders bosses have carefully planned the Kat storyline for several months and it was always the case that her current troubles would lead to her terrible decision.
As a mum-of-four with strong family ties, Kat has so much left to live for and the story will see her start to slowly rebuild her life after she survives the suicide attempt.
The emotional scenes are the start of a brand new big storyline for Kat.