Phil Mitchell (Steve McFadden) is to have an affair with former love Shirley Carter (Linda Henry). Phil - who is set to marry Sharon Rickman (Letitia Dean) - will start to see Shirley behind his fiance's back next month with a show insider promising an "explosive" time ahead for all three characters.
Viewers recently saw Shirley tell Phil that she loved him, only for the mechanic to then go and propose to Sharon. However, Sharon has now discovered that Phil was behind the attack at the Albert bar that landed her in hospital - and has secretly vowed to take Phil to the cleaners in the run-up to their wedding.
But that's not where the secrets end: Phil is one of the few people who knows that Shirley is, in fact, the mother of Queen Vic landlord Mick Carter (Danny Dyer). Could their shared subterfuge end up bringing them closer together?
"There are so many secrets and lies between these three, it's hard to keep up," a show insider admitted to the Soap Squawk website. "But one thing is for sure, it's going to be an explosive autumn in Walford."