In writer-director Andrew Cohn’s deceptively modest drama The Last Shift, fast-food worker Stanley (Richard Jenkins) is finally calling it quits. He has worked the graveyard shift at Oscar’s Chicken and Fish for 38 years, but now he’s moving from Michigan to Florida to take care of his elderly mother; grease be gone.

He’s proud of his tenure, slickly handling the drunks and the teens who ridicule him, rarely putting a foot wrong. But when he’s forced to train his replacement, the opinionated twentysomething Jevon (Shane Paul McGhie), Stanley starts to reconsider his life’s work and whatever meaning he might have attached to it. Jevon is dismissive of the job, forced into it while on probation after defacing a federal monument, and aiming to return to his love of writing when his circumstances allow. Jevon is smart but difficult, failing his beleaguered girlfriend and young son, unable to knuckle down and provide.

It’s a mismatched buddy film, but not entirely unsuccessful thanks largely to Jenkins, who can play a role such as this with his eyes closed, and McGhie who captures a mixture of righteousness and despondency. It sort of ambles along with no great imprint until a sharpish left turn as Cohn tries to transform his small-town drama into something far greater. Talk of race and class clumsily enters the picture – Jevon is black while Stanley is white – with a rushed sequence of events suddenly trying to say something about the American divide. There’s an attempt to humanise bigotry that feels a little uneasy (perhaps surer hands could have tackled this differently), and the shift in focus feels a little underpowered, with a final note that lands with a whimper.

• The Last Shift is released on 8 March on digital platforms.