By the fifth episode Bodies is a four dimensional mystery. It is also the case of you cannot trust anyone.
Julian Harker spawned a devout cult back in the Victorian era. He died in 1941 presumably by the hand of Charles Whiteman torn by the death of Esther by one of Harker's follower.
In 2023 Shahara Hasan learns more about Elias, his role in detonating a bomb that will shape the future.
The key is Iris Maplewood as Gabriel Defoe shows how the Deutsch particle caused time travel, even possibly splintering people in different timelines. That is how Mannix got back to 1890 and posed as Harker.
The older Shahara appears before Iris but she views Shahara all the others as terrorists.
The weak part of the episode is finding just who you cannot trust. Most of the superiors Charles, Alfred, Shahara are in contact with.
The strong part was the central mystery coming together and the time travel adds more layers to this.