Romantic comedies have found renewed life in recent years by leaning into unexpected premises, pairing strangers together through fate, circumstance, or the kind of chance encounter that only seems to happen in the movies. Few setups feel quite as loaded with emotional contrast as two people crossing paths mid-flight, each carrying the weight of a completely different life event.

That’s exactly the territory a new project from MRC is exploring, bringing together two acclaimed actresses for a story built around grief, heartbreak, and the strange intimacy of a shared journey. The film has been quietly filming in London amid growing media speculation about its cast and premise.

That speculation...