Walford’s latest arrival is being played by soap newcomer Ned Porteous, and it’s fair to say he’s arrived at a tumultuous time.
Michelle Fowler and Grant’s son will make his way to Albert Square after receiving a call from Phil, who discovered that he had a previously unknown nephew earlier this week.
When he gets to Walford, Mark Jr will make his way to the Beales, where Ian and Jane - who know the truth about his parentage - are waiting.
Will they stop him from discovering his true identity? Or admit the truth?
Mark isn’t the only one of Grant’s kids to arrive this month, as his daughter Courtney, conceived with Tiffany, also re-appeared just weeks ago.
This is Ned’s first big TV role, although he has previously appeared on BBC One, when he popped up in ‘Holby City’.
These ‘EastEnders’ scenes air on Friday 12 August at 8pm. Catch up on all the latest soap news and spoilers here.