Mark's story is fully revealed. When he lived in Belfast, he had a girlfriend, Siobhan Doyle. She was supposed to follow him but never did. Siobhan died soon after. His father told him she had died of TB. Instead, she had died at childbirth without him ever knowing. Mark realises how much Siobhan suffered, and is heartbroken. She was sent to a convent. To his utter shock, he finds out that the child survived: a baby girl. He tries to find her, but the nuns will not tell him anything. An accident occurs that forces him back to work: RMS Olympic, a ship in the same class as Titanic, has had a serious accident. Mark is asked to study the implications. Mark's new discoveries are now less important that delivering on schedule. Pirrie and Andrews discover that Mark Muir is a Catholic, but guard his secret.

Titanic's sister ship, the Olympic, is damaged again. Mark can't leave. Sofia also has to postpone her plans. Pietro has been injured at work and she must look after him. Mark and Andrews look for new solutions. The gashes in Olympic suggest that the steel is just too weak. Eventually they have to concede that the steel, combined with the sheer scope, is just not good enough. The double hull would have protected the ship - Perhaps the bulkheads too. For this to become a serious problem, Titanic would have to crash into something very solid. An occurrence that seems remote on the Atlantic Ocean. While Mark and Andrews slowly come to their conclusions, Emily is sentenced to an astoundingly unfair six months in jail. But another terrible event occurs: Conor is shot dead while the Unionists start advocating a new, separate State, Northern Ireland.