Rival soaps Coronation Street and EastEnders are to join forces for a one-off episode in honour of Children In Need.
Favourite characters from each show are taking part, including Kym Marsh, Beverley Callard and Jessie Wallace.
Shane Richie, who plays Alfie Moon, said it was "very surreal" filming with Coronation Street stars on Albert Square.
The mini-episode will be part of a live seven-hour show on Friday.
Callard, who plays Liz McDonald in Coronation Street, said: "I've visited the EastEnders set many years ago but this is the first time I've worked on it and it was great. We've had a great time and the script is so funny."
Whitney Dean, who is played by Shona McGarty, revealed she had shot a scene with Coronation Street's Jason Grimshaw, played by Ryan Thomas.
"We've been dancing [and] Alfie and Michelle have been singing," she said.