Every Monday, 49-year-old Ellie looks after her grandson Josh. She loves him more than anything else in the world. The only thing that can mar her happiness is her husband's affair. But he swore it was over, and Ellie has decided to be thankful for what she's got.

Then one day, while she's looking after Josh, her husband gets a call from that woman. And for just a moment, Ellie takes her eyes off her grandson. The accident that happens will change her life forever.

Because Ellie is hiding something in her past.

And what looks like an accident could start to look like murder...