Our Betrayal: Part 1 (S02E07)

Captain Jackson's reckless and untrustworthy elder brother arrives in Whitechapel carrying a valuable uncut diamond. Reid and Flight are drawn to the plight of a local craftsman defrauded of his income by a long-firm scam. Long Susan finds herself powerless to resist the ever-encroaching influence that Silas Duggan is determined to exert on her life. (BBC)