Christmas is a time for family, but across the UK this year more than 400,000 NHS workers will be giving up time with their loved ones to care for patients on Christmas Day. The chief executive of one hard-working district general hospital in Britain thinks her staff could do with a festive boost and welcomes Gareth Malone in to help put on a special Christmas concert. Gareth embeds himself in the busy Watford General Hospital, enlisting the help of staff, patients and their families from right across the hospital, to produce a concert full of wonder for everyone to enjoy.