An outstanding cast, a weighty subject, and the sincerest of intentions are almost enough to make up for an undercooked, stuntish, and stagey script in this story about a man who decides to die and the family he leaves behind.

The always-brilliant Richard Jenkins plays Robert, who has been fighting cancer for twelve years, eleven and a half longer than his doctors expected. We get a glimpse of him in a flashback, superbly confident and capable as he crisply guides a boardroom through the details of a complicated transaction and then leaves them behind to take his adored and adoring 14-year-old son Jonathan to lunch.

Garrett Hedlund plays Jonathan at 26 and we first see him getting in trouble on an airplane for smoking in the lavatory, and then persuading a flight attendant not to have him arrested with charm — and a request for sympathy because he is on his way to be with his dying father. He is on his way to be with his dying father, but we get the idea that he has been using that as an excuse for a long time.

This visit is different, though. While Jonathan and his mother Rachel (the lovely Anne Archer) and lawyer sister (“Downton Abbey’s” Jessica Brown-Findlay) tell Robert that he can get through this as he has so many times before. But he says, “I fought for 12 years. I’ve got nothing.” He wants to be taken off the drugs so he can see his family clearly. And then he wants them to let him go.

He has a surprise for them. He has given away his money. “I love you both and I raised a couple of spoiled brats,” he tells them.

It takes about a day to sort this all out, and a lot happens. Some of it is touching, as when Hedlund explains why he has stayed away: “It’s hard to love someone with an expiration date stamped on his forehead.” And he did not want to come home until he could be proud of what he had accomplished. Jonathan has to admit that he is the one who is not ready. Rachel is devoted but shows some asperity when no one acknowledges the challenges she faces as the caretaker.

But too much seems artificial. Jessica Barden, like many of the other actors, does far more than it is fair to expect with an underwritten role. In her case it is the plucky dying teenager who just wants to know what one of the normal pleasures of adolescence might feel like, which gives Jonathan an opportunity to duck out on his family as a personal Make-A-Wish, with a chorus of cute sick kids cheering him on. There is a sort of seder in the hospital chapel and an impassioned oral argument. Amy Adams shows up as Jonathan’s ex and Terrence Howard and Jennifer Hudson are the doctor and nurse. All three are sensitive performances in underwritten parts. Issues and hostilities between family members appear and disappear without the underlying emotional heft necessary to provide a reason for the changes. When Robert says he is proud of Jonathan, it is hard to understand why. And yet Jenkins and Hedlund find something in the moment that makes it matter. Writer/director Andrew Levitas shows promise, but he needs to trust his audience a little more.

Parents should know that this film deals with issues of death and dying, including assisted suicide, and it includes smoking, drinking, drugs, sexual references, and strong language.

Family discussion: Who should decide when someone should be allowed to die? Have you discussed your wishes with your family?

If you like this, try: Two Weeks with Sally Field