David, a talented architect, is excited to start his new job in London and impress his boss, Victoria. However, he soon realizes that his relationship with Victoria's daughter, Sarah, is going to make things complicated. Despite trying to keep their relationship a secret, David's coworkers discover the truth and he feels increasingly anxious about what Victoria will say.
As the holiday season approaches, David realizes he hasn't found the perfect gift for Sarah. He spends evenings wandering around London's Christmas markets, trying to come up with an idea, but somehow nothing feels quite right. When he finally decides to buy her a gift card, he feels disappointed in himself for not being more creative.
However, when Sarah opens her gift on Christmas morning, she seems genuinely thrilled with the gift card. As she explains how she's always wanted to buy a certain item, David realizes that the perfect gift isn't always the one you expect. In the end, the two of them share a romantic holiday together, filled with snowball fights, ice-skating, and plenty of silly traditions. When they return to work, David is surprised to find that Victoria doesn't seem to mind their relationship at all - in fact, she's pleased that her daughter seems so happy.