After celebrating his 29th and - as everyone including himself knows - last birthday, James, a young man terminally ill with cancer, sets out on a last hiking trip with his three best friends, Davy, Bill and Miles.
James is too weak to walk much any more, so he mostly sits in a special cart and needs a lot of very practical and physical help from his companions, in addition to liquid morphine and other medications at increasing frequency to manage his chronic pain and other symptoms.
Traveling over the rugged and isolated coastal terrain, the young men fool around having light-hearted, juvenile fun to give James the time of his life.
On the night they finally arrive at Barafundle Bay, James reveals the true purpose of the trip: he plans to drown himself in the sea before pain takes his life over completely.
Horrified at the thought, they refuse; however, after temporarily losing James's morphine supply and witnessing him struggle with severe pain, they change their minds.