Ep 1. Episode 1

Unforgotten Season 4 is an intriguing crime drama series that is centered around the cases of DCI Cassie Stuart (played by Nicola Walker) and DS Sunny Khan (played by Sanjeev Bhaskar). The series is produced and written by Chris Lang, and follows the two detectives as they investigate cold cases from the past, using their intuition, and wits to uncover the truth and bring the culprits to justice.

In season 4, episode 1, the opening scene shows a body being pulled out of a suitcase that has recently been dug up from a field. The suitcase is old, dirty and has been buried for years. Once the cops are alerted, DCI Stuart and DS Khan are called in to investigate the case, much to their initial dismay as they thought they had left this kind of work behind. However, they agree to take on the case, and the scenes transition to DCI Stuart and DC Khan's respective lives.

DCI Stuart is shown to be having dinner with her father, Martin (Peter Egan), who is suffering from dementia. Stuart's devotion to her father is evident as she patiently helps him find his words and engages him in conversation when he struggles. However, he seems to be fixated on a conversation they had in the past about a case. DC Stuart appears concerned for her father's condition and appears to be actively searching for some kind of memory aid to aid his condition.

DS Khan, on the other hand, is shown to be coping with the breakup of his long-term relationship, as he returns home to an empty apartment. He appears to be in good spirits, however, as he dances and sings along to the radio in a moment of joy.

The two detectives reunite, however, when they meet up to discuss the case, and the significance of the luggage revealed itself. The suitcase is revealed to have been the subject of a similar investigation around 30 years ago. The detectives begin to investigate the case from this angle and identify the case as the death of a teenage girl who had gone missing in 1990.

The twist comes when the detectives realize that the girl's passport was found in the suitcase, but the victim was not the one recorded to have it last. From here, there is a sequence of flashbacks and uncovering of secrets that leads the viewers to a mysterious rabbit hole of unexpected twists and turns that would leave them on the edge of their seat.

In this episode, we are also introduced to some new characters who are relevant to the investigation and whose background and involvement in the case will be revealed as the series progresses. One of the characters, Ram Sidhu (a divorcee), is shown to be going through an evidently difficult divorce case. It is also revealed that he owned the suitcase purchased in the early 90s, which is the thing that connects him to the investigation at the moment.

The episode ends with DCI Stuart and DS Khan going through the items found in the suitcase that was unearthed from the field. There are a few anomalies that the duo discovers which will put them on new paths and keep fans eagerly waiting for episodes to come.

Overall, Unforgotten Season 4 Episode 1 is a great start to the season. The episode is captivating, intriguing, and suspenseful. The characters are well portrayed, and the cinematography is top-notch. The plot is full of twists and turns and promises to bring viewers to the edge of their seats. Fans of the series will appreciate the season owing to the unique case, character development, and unexpected revelations, while newcomers will be invested in the new storyline.