‘I’m at once full of dread / and in complete denial,” writes Muldoon in the opening poem to this, his 12th collection. “I cannot thole the thought of Seamus Heaney dead.” The lines are dropped like a stone into the 27-stanza “Cuthbert and the Otters” a poem commissioned for the Durham book festival in 2013, and read there only a matter of weeks after Heaney’s funeral, where Muldoon was both eulogist and pall-bearer. “Thole”: to bear, to suffer. It’s a dialect word familiar from both poets’ childhoods, and the word (tholian) which gives Heaney “a little passport”, as he termed it, from Co Derry to the Anglo-Saxon world of Beowulf. “Cuthbert and the Otters” weaves together multiple histories: Vikings and Celts jostle for space with “the 82nd Airborne” and “Montgomery of Alamein”; the “coalfields of South Shields” with south Derry. The story of “Cuthbert of Lindisfarne / whose body will be carried aloft by monks fleeing those same Danes” finds its parallel with the cortege winding its way from Dublin to Bellaghy. The north-east of England is saturated with the language of Heaney’s north of Ireland soul-landscape: blackberries, cattle, the “peat stain”, the Viking traces. Muldoon closes with “Refulgent all. From fulgere, ‘to flash’” - evocative of Heaney’s own sensuous language, and the “lightning” strike of inspiration affirmed in the elder poet’s early essay “Feeling into Words”.

No one can do this kind of involved poetic narrative better than Muldoon. The connections made are apparently serendipitous, and all the more compelling for that. His technical and linguistic brilliance is probably second to none; the poems are the textual equivalent of a high-wire act, with juggling. So expected now, indeed, may be his virtuoso handling of the unexpected, that the moments which genuinely shock can be those slightly jarring lines where the poet chooses to expose himself at ground level, without the tricks of the trade. If arcane language puts some barriers between the self and a truth he doesn’t want to face, at other times the straight-talking, tonally less familiar Muldoon also intrudes - almost involuntarily it seems - on his own complex poetic structures: “We come together again in the hope of staving off // our pangs of grief”; “As for actually learning to grieve / it seems to be a nonstarter”.

In a recent interview, Muldoon observed that “the minute one thinks one knows what one’s doing … one’s probably making a terrible mistake. That’s … the most difficult thing to learn.” “Who’s to know what’s knowable?” is a question he posed in an earlier book (Mules, 1977). In a 21st-century context where everything seems instantly “knowable” for everyone, where we are “assailed by information”, what is “worth knowing” or what remains unknowable have become pressing questions. Unsurprisingly, a fugitive Keats - “Beauty is truth, truth beauty, - that is all / Ye know on earth, and all ye need to know” - lurks in the pages of this collection; or, as Muldoon has it in “Recalculating”, “Earth is to all ye know as done is to dusted”. The earth, however, is now also a Google Earth, and “all ye need to know” there at the touch of a touchscreen. An earlier Muldoon’s work might have required an Encyclopedia Britannica to hand, together with the 10-volume edition of the Oxford English Dictionary - or, indeed, the Pearson’s Weekly One Thousand Curious Things Worth Knowing (1904), the book presumably consulted by his father on the subject of “how to remove the merry-thought [wishbone] of a fowl” (The Wishbone is, incidentally, the title of one of Muldoon’s collections). These days, it’s tempting to read him with the book in one hand and an iPad in the other. Without the internet, some of Muldoon’s references are probably unintelligible to the reader. Where his first pamphlet, from 1971, was entitled Knowing My Place, this work, tellingly, is of “Things Worth Knowing”. As Muldoon’s career has progressed, the allusive fabric of the poems has become increasingly private and elusive as it has also, paradoxically, become more expansive, moving further away from a “knowable” point of origin. He’s become, in other words, harder to “place”.

Muldoon’s own awareness of a changing context is more explicitly the subject of this book than any previous collection. It’s as if, conscious of both literal and virtual surveillance - see “Rita Duffy: Watchtower 2” - the poems try to keep one step ahead, resistant to being “decoded”, offering a Muldoonian form of counter-surveillance in which every square mile (or sonnet) is densely packed with information. Like Lewis Carroll’s Walrus, Muldoon talks “of many things” - if not shoes, ships, sealing-wax, cabbages and kings, then chickens (quite a lot of chickens) and horses, saffron and civil war, bicycles and barrage balloons. But it’s a collection that poses more problems for its reader than simply chasing the relevant “data”, or checking the “facts” (some of which are unexpectedly right; others - like the body temperature of a chicken - probably wrong).

The long poem that closes the book is “Dirty Data” (“dirty data”: computer data that contains erroneous information - misleading, duplicated, inaccurate, incorrectly spelled). It’s a tour de force, addressed to Lew Wallace, in which Ben Hur meets Bloody Sunday and the Troubles. It’s full of dirty data - the misquoting of Churchill (“Such is the integrity of their kraal”), the misphrasings ( “Ben Hourihane / falls fuel of the new Roman turbine”; Pilate’s hanky “swerves as a morning”). It tells “dirty” and contested (and repeating) histories too in which the “data” itself is in dispute. As such, its own intricate patterning of lines and stories ( “To add to the confusion”) raises questions about the patterns and structures imposed, out of the relentless stream of (mis)information, on the telling and interpretation of history. In this, it may well be - as his closing line has it - “a wickiup call” for our time.