Mr. Hughes’s early life was darkened by shadows of depression and suicide. Ms. Plath explored the themes in her 1963 novel “The Bell Jar,” which follows an ambitious college student who tries to kill herself after suffering a nervous breakdown while interning at a New York City magazine. The novel reflected Ms. Plath’s own experiences, including her early struggles with depression and her attempt at suicide while working at Mademoiselle in New York as a college student.

After a stay at a mental institution, Ms. Plath went on to study poetry at Cambridge University, where she met Ted Hughes, who was on his way to world fame as a poet. The two were married in 1956, and had two children  Nicholas and Frieda  but separated in 1962 after Mr. Hughes began an affair with another woman, Assia Wevill. Ms. Plath killed herself at the age of 30 by sticking her head in an oven in her London home on Feb. 11, 1963, as Nicholas and Frieda slept nearby.

Six years later, Ms. Wevill, who had helped raise Nicholas and Frieda after Ms. Plath’s death, killed herself and her 4-year-old daughter, Shura. Ms. Wevill styled the murder-suicide in the same manner, using a gas stove.

Mr. Hughes, who became Poet Laureate in 1984 and was widely regarded as one of the greatest poets of his generation, resisted speaking openly about the deaths for many years. But in his last poetic work, “Birthday Letters,” published in 1998, he finally broke his silence and explored the theme. He died the same year, as the book  in some ways considered a quest for redemption  was climbing best-seller lists.

Mr. Hughes was said to have protected his children from details about their mother’s suicide for many years. But in at least one poem he seemed to indicate that Nicholas, who was only 1 at the time of her death, was pained even as a small child, recalling in one stanza how Nicholas’s eyes “Became wet jewels/ The hardest substance of the purest pain/ As I fed him in his high white chair.”