As the U.K. Christmas ad season kicks off this week, among the heartwarming spots on offer is one that's a little more bleak; although at fist you might mistake it for typical holiday fare.

The spot by Don't Panic for homelessness charity Shelter features a little boy who forces a smile onto his face even when things go wrong. We first see him practicing his smile in front of a bathroom mirror at school to the soundtrack of "When You're Smiling" by Dean Martin;  at this point, viewers might be lulled into thinking this is going to be a spot about a cute kid.

As things go wrong throughout the school day -- bad marks in homework, letting in a goal at football, no pudding at school lunch -- he puts on the same forced smile. But when he goes home, we see his reality, as his mother leads him to a bare room in a noisy apartment block and tells him this is where they will be spending Christmas. 

“We wanted our audience to fall in love with young Jayden, to smile, or even laugh, along with him," said Rick Dodds, creative partner at Don't Panic and writer of the spot, in a statement. "The more people enjoy the first half of the film, the more poignant and frankly heartbreaking it is when the spot reveals the reason he’s been practicing his goofy smile and his stark homeless reality."

The agency worked closely with Shelter to ensure that every detail of the temporary accommodation was an accurate representation of where the boy and his mother could be spending Christmas.

The spot, running on TV and social channels, was directed by Si & Ad via Academy, who commented on the choice of music: "Dean Martin’s voice manages to carry both happiness and sadness in equal measure. The recording also has a huge sense of nostalgia that plays perfectly into the Christmas narrative. Dean Martin himself died alone on Christmas day which adds further poignancy and meaning to using this version."