Kat (played by Jessie Wallace) does not currently know that her cousin Hayley (Katie Jarvis) had a one-night stand with her alienated husband Alfie Moon (Shane Ritchie), leading to the birth of her newborn daughter on EastEnders.
However, it appears that Kat, without knowing this information, could be involved in a plan to separate Hayley from her baby.
The conspiracy will end next week when Bev Slater (Ashley McGuire) returns to the BBC soap and apparently wants to help her daughter Hayley.
Bev, however, has not changed and is soon up to her old tricks when she manipulates Hayley to believe that she can not cope with her newborn child.
Hayley's ruthless mother will come back later this week as Hayley has to go to hospital after receiving her daughter.
Hayley was seen leaving the baby at the front door last night. However, when she sees that her baby needs her, the new mother has a change of heart when she gives her daughter away.
Bev arrives at the hospital to take Hayley and the baby home and seems to encourage Hayley to connect with her child.
Next week, however, the façade falls off soon after Bev plays off her daughter's vulnerability and begins to manipulate Hayley.
When Bev unites the mother with her child, she begins to drip, feeding Hayley with criticism of her maternal abilities, and soon finds herself spending some time with the dead.
When Hayley is out of the room, Bev takes a picture of the child and then calls the authorities – and Hayley returns to the room.
Hayley is appalled by her mother's actions and confronts Bev, who tries to reassure her daughter that she is doing the best.
Kat and Jean Slater (Gilliam Wright) do not believe that Bev is trying to help and also confront the alienated family member about their intentions.
Hayley tells the couple that Bev wants her to give the baby away, but Kat does not know about it and tells Bev exactly what she thinks of her.
However, Bev manages to make Kat think, as she later tells her that she will give Kat part of the money by helping her manipulate Hayley.
Will Katy Hayley betray some cash because of the difficulties he has had in the past, or will the loyalty of the family be exaggerated?
Alfie is soon ready to return to the square to meet up with his strange wife, but he could come back to help Kat leave quickly after her betrayal was discovered.
If Kat finds out that the baby is Alfie's, will she stay to make Hayley's life a miserable one?
Viewers of the BBC soap will have to see if Kat accepts the offer, but one thing is for sure: When they discover the truth about the child's paternity, there will be fireworks.
Elsewhere in Albert Square, Carmel Kazemi said goodbye to Walford last night when actress Bonnie Langford left soap after three years.
The departure of Bonnie had completed her degree in knife crime story when her son Shakil Kazemi (Shaheen Jafargholi) was murdered earlier this year.
EastEnders continues tonight at 7:30 pm on BBC One.