Josh O'Connor and Olivia Colman are two of the hottest stars of UK TV and film right now, and they clearly love working together. As well as playing mother and son in The Crown, they both took major roles in the BBC production of Les Miserables. But, while Olivia gets down and dowdy as Madame Thénardier, Josh is giving us another take on a romantic hero as he portrays Marius Pontmercy, who has one eye on justice and the other on love.