John Harmon has been away from England for someone time. Not just away as in traveling and seeing the world; he has been a man in exile, cast adrift by a father with far more material wealth than overabundance of understanding of his son. The hard old contractor has since died and John views this turn of events as his chance to rightfully claim his inheritance. In fact, with his father out of the way, only one thing stands between him and that claim: the stipulation that he must marry Bella Wilfer in order to collect it.
The full extent of John’s knowledge of Bella is her name. So he devises a plan to return home under an assumed identity just long enough to allow him to get a completely objective perspective on the character and deportment of this mysterious stranger into whose hand his father has passed the key that unlocks his entire future. Harmon divulges this plan to seaman on the ship which is his transport home. That sailor wastes little time in making his play for what sees as his once-in-a-lifetime opportunity to making a grab for the golden ring.
While carrying out his own plan to murder John and assume his identity, the sailor is himself murdered and his body tossed into the river as well. The only difference is that John manages to survive his injuries while the sailor dies. When his body is discovered a few days later, the fact that John’s personal effects are found in the dead man’s pockets naturally leads to the conclusion that the mate actually was John and that the heir to the Harmon estate is now dead.
Fortunately, this bizarre twist of fate fits perfectly into John’s original plan and so he takes on the name John Rokesmith as he finds employment as the secretary for Mr. Boffin, his father’s long-time factory foreman. The news of the apparent demise of the younger Harmon resulted in Boffin inheriting the estate. Boffin adopts the initially spirited if somewhat capricious Miss Wilfer, but exposure to wealth soon tears away the admirable veneer of her personality, leaving here merely predatory and verging on the larcenous. Enough of what lies beneath is recognized by John that he fulfills the necessary narrative role of falling in love with her. This situation sets up another expectation for the reader that is confirmed, though doubtlessly is not what the true heir to the monied root of the evil turn in her character quite expected.
She contemptuously rejects his declaration of love. The discovery of the true identity of Mr. Rokesmith by Mrs. Boffin just about coincides with this ricochet of Cupid’s arrow from its true course. The Boffins are convinced of the underlying basic decency of Bella and, not only feel a natural fondness for John, but were raised as part of that strata of British society that is perfectly conditioned to place the interests of their employers above their own selfish desires even what that employer is long done dead. The synchronicity of this strong emotional bond and the deep-seated effects of social engineering on the Boffins move them to develop and implement a strategy by which Mr. Boffin seems to have become far more corrupted by his newfound wealth than Bella might even be capable.
Boffin also assumes a false identity of a sort by transforming into a much lighter prototype of a far more famous Dickens character whose soul had been corrupted by greed. The phony Scrooge-act culminates in John Harmon being sent into exile for the second time, albeit in the guise of Rokesmith. This manifestation of the evil influence of wealth also brings about a reset in Bella to the kindly if scattered soul she was upon first arriving and this, in turn, forces a reappraisal of her rejected suitor.
The only thread left untied is the revelation of the true identity of Rokesmith as the true heir to the estate that has also served to make Boffin the target of a blackmail subplot which is also successfully addressed.