Glasgow, 1817: Jean Campbell – a young, Deaf woman – is witnessed throwing a child into the River Clyde from the Old Bridge. If found guilty she faces one of two fates; death by hanging or incarceration in an asylum.

But Jean's deafness leaves her isolated and unable to defend herself, until the authorities call in Robert Kinniburgh, a talented teacher from the Deaf & Dumb Institution. Through a difficult process of trial and error, Robert and Jean manage to find a rudimentary way of communicating with each other. As Jean grows to trust Robert, she reveals what really happened on that bridge over the river Clyde. And Robert, now embroiled in this dark case, must act quickly to ensure justice is served, before it is too late.