Kat Slater will find herself in serious danger after a smoke bomb is thrown into her house with the children inside.
She immediately knows who's behind it and is shaken, but tries to remain calm about the situation.
However, her fear escalates when she receives a strange package - thankfully, she and Stacey are relieved to discover that it's a false alarm in the cafe.
Kat ( Jessie Wallace ) goes on to admit to Stacey that she didn't want to live a life like this and it wasn't the reason she was with Phil.
Denise ends up overhearing their chat and suggests that they sort everything out with Sam so she can leave Jack and their family alone.
Later in the Square, Ben manages to rile up Kat by saying that she's not up to being a Mitchell. When Sam arrives at her house to say she's moving in, Kat throws her out and declares that she is the head of the family now.
But at the end of the week, Kat is shocked after Callum escorts Lily home after she was seen shoplifting.
Kat quizzes her on what's going on and why she did what she did, but she is shocked by Lily's response...
It comes after Sam - played by Kim Medcalfe - reprised her role on the BBC soap for the first time in nearly 17 years last night.
Since her last appearance in 2005, Sam has been played twice by original actress Danniella Westbrook, but now Kim is back in the role for new scenes.
On Monday night, she made a surprise appearance as she visited her brother Phil Mitchell in prison.
The character had been called back by Phil, and her real reasons for being in Walford again will soon be exposed.
Viewers were quickly rejoicing over her being back on screen, as others commented that actress Kim didn't look any different 17 years on.
Taking to Twitter, one fan said: "Kim Metcalf has not aged a DAY. The best Sam Mitchell has returned."
Another agreed: "OMG Sam is back ! She looks absolutely TANTALISING How has she aged this well?," as a third added: "Sam hasn’t aged all these years."
*EastEnders airs Monday to Thursday at 7.30pm on BBC One
