Ariel's Gift: Ted Hughes, Sylvia Plath and The Story of Birthday Letters, by Erica Wagner (Faber & Faber, £8.99 in UK)

When Ted Hughes's collection Birthday Letters was published in 1998 it caused a sensation, and no wonder

When Ted Hughes's collection Birthday Letters was published in 1998 it caused a sensation, and no wonder. It was, as Erica Wagner puts it in her introduction to Ariel's Gift, "a book no one ever expected to see": an extraordinarily intimate outpouring from a notoriously reticent poet and a vivid recreation of his relationship with his first wife, Sylvia Plath, whose suicide in 1963 stunned the literary world. The appearance of this eloquent and complex cycle of poems was swiftly followed by Hughes's death from cancer - but fascinating as they are, the poems are, too, a puzzle. Did Hughes mean them as catharsis or atonement? Why would a poet who had always turned outwards, to the natural world, to mythology and anthropology, suddenly turn inwards and produce one of the most personal collections of poetry ever written? In this clear-headed study Wagner sets the poems in their real-life context, tracing the batting of ideas back and forth between Hughes and Plath, while refusing to take sides in any personal battles. And, Ariel's Gift is an indispensable book to have by your side, when approaching the work of either, or both.

In the Heart of the Sea, by Nathaniel Philbrick (Harper Collins, £6.99

Arminta Wallace

Arminta Wallace

Arminta Wallace is a former Irish Times journalist