M. John Harrison is an immersive, stunning literary stylist who has written several science fiction classics, but “The Sunken Land Begins to Rise Again” is something altogether different. It follows Shaw, a drifter through life who takes on a job on a tumbledown London barge, and Victoria, Shaw’s sometime lover and also a scrambled person, as she settles into the family home in Shropshire. Nothing much happens—the two of them get together, part, and drift onwards, but around them something strange is happening in the waters, in the towns, everywhere … small oddities that build up into a sense of an ancient, menacing otherworld. Harrison cannot write a dull sentence, indeed the sentences overflow with piercing descriptions of a Britain in post-Brexit decline. “The Sunken Land Begins to Rise Again” is a beguiling, aslant tour de force.