Vicious tells the story of ageing partners Freddie and Stuart; two men who have lived together in a small Covent Garden flat for nearly 50 years. Freddie was a budding actor and Stuart a barman when they first met but their careers are now pretty much over and their lives now consist of reading books, walking their dog and bickering.

Joining Freddie and Stuart is feisty best friend Violet. She's young at heart with a delicious sense of humour and always on hand to calm Freddie and Stuart down during one of their many arguments. Also part of their long-standing friendship group is dizzy Penelope and grumpy Mason.

Freddie and Stuart's worlds are turned upside down with the arrival of a young man, Ash, as their new upstairs neighbour.