The End of Her - Grand Format

It starts with a shocking accusation... Stephanie and Patrick are recently married, with newborn twins. While Stephanie struggles with the disorienting effects of sleep deprivation, there's one thing she knows for certain - she has everything she ever wanted. Then a woman from Patrick's past arrives and makes a horrifying allegation. He always claimed his first wife's death was an accident - but she says it was murder.
He insists he's innocent, that this is nothing but a blackmail attempt. But is Patrick telling the truth ? Or has Stephanie made a terrible mistake ? How will it end ?