Derek (Jamie Foreman) will turn against Max over the festive period after he feels disrespected by him once too often, according to magazine reports.
Viewers have seen Derek help out Max (Jake Wood) with his 'problem' over the past few months, but it seems that he will ultimately use his knowledge to destroy his brother's happiness in dramatic episodes.
Full details of the storyline are being kept firmly under wraps, but it's thought that Derek ensures Max's secret is exposed to the whole Branning family.
The drama plays out after Max discovers Derek's blackmail of Tanya over the recent car crash and Lauren's short-lived relationship with Joey.
When Max takes Derek to task over his antics, the Albert Square villain is furious over his attitude and vows to make him pay.
Max's secret has been a talking point among fans since the beginning of the year, but thanks to Derek, viewers will finally get an answer at Christmas.
However, as it's well-known that Derek will be killed off in late December, will this be his last malicious act?