A couple of years back, I read Anna Jackson's Actions and Travels, her elegant, eager tread through poetry's varieties, voyages, vistas. ''She'll be hard-pressed to match that,'' I told fellow book persons. 

I was right. Terrier, Warrior doesn't match the earlier book. In some ways, it surpasses it. 

It's a silly comparison, of course. While Actions was a trip around poetry, Terrier, Worrier is an immersion in it. 

It's five separate yet continuous prose poems with subtitles from mathematics and architecture, that loop across five seasons: a year, then a second summer. They're followed followed by notes so extensive and extending, they may remind you of Eliot's Waste Land.

Stanza after stanza begins ''I thought....I wondered....I read.....I thought''. Because this is a sustained, often anecdotal rumination on the riddling, self-regarding motions of a mind: ''I wondered whether thinking that hearing the cat wasn't a thought was itself a thought''. 

What does the poet's voice think about over the seasons? Or think it's thinking about? How her pet hen shoved cats off the bed ''before laying an egg in one of the warm hollows''. A definition of cheating. Rats' and birds' dreams. The eponymous terrier-cum worrier. Ready-made exercise books. Writers and thinkers of all sorts: Virginia Woolf, Jan Morris, Wittgenstein, Emily Bronte, Madison Hamill and more.

(Pause to draw breath.) Add her grandson – I think? – Simon and his zombie-fooling techniques; a Renaissance falconry manual; how fast time advances when she's writing fiction; the sound and structure of the word ''floating''; how you can't read, drive or use cellphones in your dreams. (If you do, I suggest you contact the author.)  There's near-infinite variety in a small space. Jackson's friends, colleagues, animals and family all feature, which is – well, endearing

It may make you think of zen koans. Or of that Creamota packet from decades back, whose outside featured a laughing boy carrying on his shoulder a smaller Creamota packet showing a laughing boy carrying on his shoulder an even smaller Creamota.....ad infinitum.

I mustn't make it sound like a game, a display, though it is playful in the best sense: an exuberant, inventive series of vaults and somersaults through associations, meanings, paradoxes. It's also a meticulous meditation on what goes on inside our skulls; a quest to define identity and language, a poetic sequence much concerned with the nature of poetry: ''a form of refusal as well as openness....a refusal in its openness''. You could even see it as a self-exploration manual, though I suspect Jackson would be justifiably appalled at the idea.

It's reflective, measured, calm even at its most active. A fine mind is talking to you. Remote or rarefied? Not in any sense of removal from life and reality. It's actually an immersion in these, on several illuminating, sometimes provocative levels, often within the same stanza / paragraph.

It's rich with phrases and images that make you exclaim with satisfaction. ''I wanted to feel like a leaf but I felt like a sink full of dishes''; ''I can believe in God the way mathematicians believe in imaginary numbers'';  ''….we can open up the whole vast matchbox of the self''.

The wrapping is as elegant and attractive as the contents. ''Paperback with flaps,'' reads the publisher's note; I can imagine the phrase appealing to Jackson. It also has a clear, nicely spaced design by Greg Simpson, and nifty illustrations by Briana Jamieson, both of whom deserve multiple ticks. 

Like a lot of top poetry, Anna Jackson's darting, soaring lines finally elude the gumboot plod of any prose interpretation. A book that's rewarding to hold in the hand and the mind: what a satisfying...thought.

Reviewed by David Hill