Warleggan, the fourth novel in the twelve-book Poldark series, was written in 1953 by Cornwall's Winston Graham, and is the one book in which it can be said the stage is carefully set for the transition from the early cycle of Poldark novels, to those in the middle of the legendary series.
In this installment, Ross and Francis's partnership in the Wheal Leisure mining operation is threatened when the backing of key members of the Cornish business community begins to be inexplicably withdrawn. It soon becomes apparent that Poldark's hated foe, George Warleggan, rapidly becoming the wealthiest man in Cornwall, is pulling strings, intent on ruining the Poldarks. In addition, the results of Dr. Enys relationship with the aristocratic Caroline Penvenan drives the doctor to drastic actions, and even the marriage of two such similar souls as Demelza and Ross founders.
This is a novel in which perhaps the very deepest and most vital events in the first half of the entire series come to pass, and the one in which English society of late-Georgian times is most creatively explored, frequently even insofar as Graham seems to step away from his central characters and take asides that could only be termed "sociological." Warleggan features much financial battling, showcases Ross's nature as a gambler, and sees the death of a character who had seemed so central to the plotlines of all other books as to be indispensable, proving that in the Poldark novels nothing may ever with certainty be predicted. In Warleggan, sexual passions long buried for dead explode, disaster looms throughout the story, the forces of malignity seem prepared to achieve absolute and utter triumph, and never before have the Poldark fortunes looked so drear as near this novel's end...and then a twist comes into the plot and the novel ends in a cliffhanger that must have tormented original readers forced to wait TWENTY YEARS for Graham to release his next Poldark installment...