Just because they are identical does not mean these twins even like each other. Estranged twin sisters get together for an obligatory pre-Christmas lunch, a year after their mother died. Both women are unhappy and frustrated with their own lives.
Though not close, each is envious of the other's life. What's a twin to do but take advantage of this? And who would be the wiser? They do what any identical twins in need of new outlooks would do - they swap lives until Christmas Day.
And by doing so, each woman discovers the true meaning of her life and gains a deeper perspective and appreciation for what she already had.