Yvette Fielding assembles her team for a massive two-part Christmas investigation at the foreboding and now disused Gloucester Prison. The vast site is said to be one of the most haunted places in Great Britain, a place that has seen death, fear, pain, suicide and incarceration. A place that is built on the rotting corpses of many prisoners, a place to be feared. The team's mammoth investigation is split into two parts with the conclusion premiered exclusively on the official Most Haunted YouTube channel.