Although EastEnders detective Emma Summerhayes (played by Anna Acton) has been moved off the Lucy Beale case, she’s still committed to discovering who Lucy’s murderer is.

Tenacious Emma Summerhayes is determined to uncover the truth

Tenacious Emma Summerhayes is determined to uncover the truth

The BBC is tantalising viewers with their official trailer for the popular soap; a clip is included where Detective Summerhayes is on the verge of a massive breakthough.

Seen on the phone, she empatically says to the unknown person on the end of the line: “I know you killed Lucy.”

Hoping to tease out further details, Emma creates an explosive confrontation when she arranges drinks at the Queen Vic for the Beales and the Brannings.

How close are Lucy's family to learning the truth?

How close are Lucy’s family to learning the truth?

However, Emma quickly becomes suspicious of those at the pub, and after she goes home, attempts to sift through the evidence and figure out the jigsaw. As she reviews the footage taken on Good Friday, the night Lucy was killed, the penny drops and Emma has a revelation.

However, what will she do with that information? And what will the murderer make of it all?

This dramatic episode will air on Tuesday, 30th December at 7.30pm on BBC One.