Two years ago, when Joe Vogel agreed to write a new edition of his influential book about Michael Jackson — to be released this summer for the 10th anniversary of the singer’s death — he thought it would be demanding but gratifying work, a fresh opportunity to train his arrow on the most formidable legacy in all of modern pop, to address new questions about the artist’s collaboration with the producer Quincy Jones and to celebrate the enduring resonance of Jackson’s abundant song catalog.

Cue record scratch.

In the month since HBO debuted the explosive documentary “Leaving Neverland,” in which two men and their families accuse Jackson of sexual abuse that they say went on for years while the men were children, Vogel has instead found himself in a biographer’s nightmare, scrambling to re-examine thousands of hours of research — and his unspoken biases and assumptions — as the cultural and informational landscape lurches beneath him.

“It complicates things in ways that are just really, really challenging,” Vogel said by phone recently. “Not only are you thinking about how do you deal with this on a personal level, you’re also thinking about how to handle it professionally.”

As music fans have tried to reconcile the Jackson of “Leaving Neverland” — a brazen pedophile who left children and their loved ones in ruin — with the spellbinding “Thriller” singer whose DNA winds through generations of art and culture, the biographers and journalists who wrote him into our collective memory have quietly been retracing their steps, some with pride, some with anguish, some hovering unsteadily in between.