It's not exactly halcyon days at the Halcyon Hotel in London. World War Two is just kicking off and proprietor Lord Hamilton is struggling to keep his indiscretions under wraps, while his wife is furious, his son sulky and the other one about to go off to war. It's a lot for the Hamilton family and the hotel's staff to handle.
But in the middle of all that, there's drinking and dancing and singing as life goes on at the luxury hotel, where guests and staff are determined to have a good time.
Here are the stars of ITV's The Halcyon – described as a "sexier Downton" – and where you have seen them before:
Alex Jennings – Lord Hamilton
Who does he play? Lord Hamilton owns The Halcyon. He uses it for illicit meetings (both political and romantic) – but he runs into trouble when everything begins to unravel, with his latest affair coming out into the open and his meetings to discuss appeasement hitting the media.
Where have I seen him? Everywhere. Recently, Jennings has played both the Duke of Windsor in The Crown and King Leopold in Victoria.
Steven Mackintosh – Richard Garland
Who does he play? Mr Garland is the calm and professional hotel manager, but there's more to him than first meets the eye. He is the engine of the hotel, keeping everyone's secrets and making sure everything runs smoothly. With a strong sense of duty and responsibility, he is also prepared to get his hands dirty and outsmart his opponents to protect The Halcyon. He also has a secret he would rather forget.
Widower Mr Garland is devoted to grown up daughter Emma and will do anything to protect her.
Where have I seen him? Mackintosh is one of those actors who can turn his hand to anything. He's appeared in Lock, Stock and Two Smoking Barrels, Luther, The Land Girls, The Other Boleyn Girl and Our Mutual Friend.
Olivia Williams – Lady Hamilton
Who does she play? Lord Hamilton thinks he and his wife have an "understanding", but the limits of that understanding are tested when Lady Hamilton arrives at The Halcyon while he is in bed with his latest woman. The staff rush to stop her reaching the door, but she's humiliated to find out everyone knows what's going on. It's a tricky time for Lady Hamilton – but as a snob with a nasty streak, she's far from likeable.
"She begins thinking that she is in control, which is a wonderful delusion to have," Williams told RadioTimes.com.
"And as she walks through the door and gets closer to the royal suite, she realises that she isn't in control. And I think it's a humiliation and a tragedy and a crisis in the life that everybody dreads, the realisation that your partner is not only being unfaithful to you, but has been being unfaithful to you for a long time and everybody else knows about it."
Where have I seen her? A veteran of stage and screen, Williams has starred in Rushmore, The Sixth Sense and An Education.
Hermione Corfield – Emma Garland
Who does she play? Emma is the daughter of Mr Garland, working as a receptionist at The Halcyon – the hotel where she grew up. She's just coming of age when the war hits, and romance looks set to bloom between her and childhood friend Freddie Hamilton despite their very different positions in life. Emma is headstrong and capable, with a strong sense of justice.
Where have I seen her? This seems to be Corfield's moment. The 23-year-old recently starred in Pride and Prejudice and Zombies as well as 2015's Mr Holmes, and next year she'll be in XXX: Return of Xander Cage and King Arthur: Legend of the Sword.