The soap legend has rejoined the EastEnders cast this week after being confirmed for a comeback late last year.
Her return storyline was shrouded in secrecy, though it was revealed that her son Hunter (Charlie Winter) would be joining her.
On Tuesday night, viewers watched as the familiar face walked into The Arches and met a secretive Ben Mitchell (Harry Reid).
Ben was busy hiding the stolen goods from the New Year's Day heist while organising his getaway from Walford.
He was interrupted concealing the stash and told Mel that he couldn't help as he was busy.
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Tamzin Outhwaite's life and career in pictures

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But in these new pictures, could there be more to the story and will viewers find out why Mel went straight to The Arches?
Ben is unaware of who Mel is and that she has such a rich history in Albert Square so turns her away.
It looks like viewers could get a look into why Mel is back tonight when EastEnders returns to screens.
Speaking about Mel's return, Tamzin said: "I like [John Yorke's] view that the representation of East End London in the show works best when you have really strong women driving it."
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“He really wanted the female characters to drive it again, so it's going to be a lovely challenge”
Tamzin Outhwaite
She added to the Metro: "He really wanted the female characters to drive it again, so it's going to be a lovely challenge."
Tamzin isn't the only strong female star making her return to the Square, as confirmed by EastEnders at the end of 2017.
With Stacey Fowler (Lacey Turner) having a bit of a wobble over Christmas and sleeping with Max Branning (Jake Wood), her family return to sort her out.
That means Jean (Gillian Wright), Big Mo (Laila Morse) and Kat (Jessie Wallace) will all be making their comebacks this year.
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Meanwhile, Ben will be bowing out, while Lauren Branning (Jacqueline Jossa) is also leaving after surviving her fall from the Queen Vic roof.
Her sister Abi (Lorna Fitzgerald) is still in the soap on life support but is set to have her final scenes next week.
EastEnders continues tonight at 7.30pm on BBC One.