Inside Vigil, the BBC thriller mixing murder, secrets and a lesbian love story

The BBC’s Vigil combines murder investigations, military secrets and international conspiracies with a love story between two women. Starring Suranne Jones as DCI Amy Silva and Rose Leslie as DI Kirsten Longacre, the thriller has taken its detectives from a nuclear submarine to a military investigation and, most recently, a remote Arctic research station.

The series takes its name from HMS Vigil, the fictional nuclear submarine at the centre of the first series. When a crew member is found dead aboard the vessel, Amy is sent to investigate, uncovering a case that reaches far beyond the submarine itself.

Across three series, the drama has developed Amy and Kirsten’s relationship alongside increasingly dangerous investigations.

Their personal lives, including Amy’s traumatic past and their plans for a family, are just as important to the story as the mysteries they are trying to solve. If you are new to Vigil, or need a reminder of what happened before watching the latest episodes, here is how the story has unfolded.

Amy Silva’s past and her relationship with Kirsten

Before the first series, Amy suffers a devastating loss. She was in a relationship with Iain Torrens and helped raise his daughter, Poppy. When their car crashes into a loch, Amy saves Poppy but cannot rescue Iain, who drowns. Poppy subsequently goes to live with her paternal grandparents, leaving Amy grieving both Iain and the child she helped bring up.

The accident leaves Amy struggling with grief and guilt, as well as claustrophobia. These difficulties become particularly challenging when she is sent to investigate a death aboard a submarine, where she is confined in an enclosed space far from home.

Amy also has a complicated history with Kirsten. The two women were previously in a relationship, but they separated because Amy struggled to let Kirsten fully into her life. When they work together on the submarine case, their feelings for each other return, and they begin rebuilding their relationship alongside their demanding police careers.

As the series progresses, Amy and Kirsten work towards a future together, with Poppy part of their family and a baby on the way by the second series.

Their relationship remains central to the drama as they try to balance family life with investigations that repeatedly put them under pressure.

Series one takes Amy aboard HMS Vigil

The first series begins when a crew member is found dead aboard HMS Vigil, a British nuclear submarine on patrol.

Amy is sent aboard to investigate, but the crew’s reluctance to cooperate makes her task difficult. Meanwhile, Kirsten conducts enquiries on land, where she begins uncovering information about a possible cover-up.

As the investigation develops, Amy discovers that the death is connected to a much greater threat. The case brings the detectives into conflict with powerful institutions and forces them to question whom they can trust.

The submarine setting gives the first series its distinctive atmosphere. Amy must work in a confined environment, separated from the outside world and under pressure to find answers. Her claustrophobia adds another challenge, while her conversations with Kirsten bring their unresolved relationship back into focus.

Series two explores military drone warfare

The second series moves away from the submarine and into the world of military technology. After a weapons test at a Scottish airbase goes wrong, seven people are killed, and Amy is called in to investigate.

The incident involves a military drone and becomes the starting point for a wider conspiracy involving British defence interests and the fictional Middle Eastern nation of Wudyan.

Working across different locations, Amy and Kirsten investigate a case that draws in military personnel, political interests and questions about how weapons technology is being used. As they get closer to the truth, the danger increases and Amy finds herself caught up in events far beyond a straightforward police investigation.

Away from work, Amy and Kirsten are building a family together. Their relationship has developed since the first series, but the pressures of their jobs continue to complicate their personal lives.

Series three takes the detectives to the Arctic

The third series sends Amy and Kirsten to Svalbard, a remote Norwegian archipelago in the Arctic. When a member of a covert British special forces mission is shot dead at a research station, the investigation quickly becomes politically sensitive.

Kirsten investigates in the Arctic, while Amy looks into connected events in Scotland. The case becomes more complicated when microbiologist Shen Jia goes missing, raising questions about what she has discovered and why powerful interests might want to find her.

The detectives find themselves caught up in tensions involving several countries, with the Arctic’s resources and changing climate adding to the stakes. As the investigation unfolds, they must work out who can be trusted and try to prevent a potentially serious international confrontation.

The remote setting creates a different challenge from the submarine in series one. Political tensions, uncooperative witnesses and the dangers of the Arctic environment all complicate the search for answers. Amy and Kirsten’s relationship is also under pressure as the case threatens both their careers and their future together.

Where to watch Vigil

All three series of Vigil are available on BBC iPlayer in the UK, including all six episodes of series three.