It is deep autumn, and Sam (Colin Firth) and Tusker (Stanley Tucci), partners of twenty years, are on holiday. They are travelling across England in their old campervan visiting friends, family and places from their past. Since Tusker was diagnosed with young-onset dementia two years ago their lives have had to change. Jobs have been given up and plans put on hold. Their time together is now the most important thing they have. As the trip progresses, their individual ideas for their future begin to collide.
Secrets are uncovered, private plans unravel and their love for each other is tested like never before. Ultimately, they must confront the question of what it means to love one another in the face of Tusker's irreparable illness.