The engineers focus on the interiors, fixtures and fittings of the Titanic, and rediscover the lost skills of British craftsmen and women by re-creating the centre section of the most expensive room on board the ship - the gentlemen's first-class smoking room. They also build the more humble third-class cabin, which still represented working-class luxury in its day, and unveil both replicas in an exhibition at Belfast's biggest museum, with surprising results.