Seven well-known personalities with differing faiths and beliefs put on their backpacks and waterproofs and set out travel more than 1,600km on foot and by road and sea to learn about St Columba, a key figure in early British Christianity. Following ancient paths and heritage walking trails are interior designer Laurence Llewelyn-Bowen, former England cricketer Monty Panesar, actress Louisa Clein, TV presenters Nick Hewer and Scarlett Moffatt, comedian Shazia Mirza and Paralympian Will Bayley